[fd775ae] | 1 | #include <fstream.hfa> // sin/sout |
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| 2 | #include <stdlib.hfa> // convert |
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| 3 | #include <string.h> |
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| 4 | #include <coroutine.hfa> |
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| 5 | |
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| 6 | struct Potato { |
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| 7 | PRNG & prng; |
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| 8 | unsigned int deadline; // when timer goes off |
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| 9 | unsigned int timer; // up counter to deadline |
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| 10 | }; // Potato |
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| 11 | |
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| 12 | void reset( Potato & potato, unsigned int maxTicks = 10 ); |
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| 13 | void ?{}( Potato & potato, PRNG & prng, unsigned int maxTicks = 10 ); |
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| 14 | |
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| 15 | void ?{}( Potato & potato, PRNG & prng, unsigned int maxTicks ) with(potato) { |
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| 16 | &potato.prng = &prng; |
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| 17 | reset( potato, maxTicks ); |
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| 18 | } // Potato |
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| 19 | |
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| 20 | coroutine Player { |
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| 21 | PRNG & prng; |
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| 22 | int id; // player identity |
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| 23 | Potato & potato; // potato being tossed |
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| 24 | Player * partner[2]; // left and right player |
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| 25 | }; // Player |
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| 26 | |
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| 27 | void ?{}( Player & player, PRNG & prng, unsigned int id, Potato & potato ) { |
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| 28 | &player.prng = &prng; |
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| 29 | player.id = id; |
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| 30 | &player.potato = &potato; |
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| 31 | } // Player |
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| 32 | |
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| 33 | Player & umpire; |
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| 34 | |
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| 35 | ExceptionDecl( Explode ); |
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| 36 | ExceptionDecl( Terminate, Player * victim; ); |
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[26be854] | 37 | ExceptionDecl( Election ); |
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[fd775ae] | 38 | ExceptionDecl( cmd_error ); // convert(...) throws out_of_range or invalid_argument |
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| 39 | |
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| 40 | void reset( Potato & potato, unsigned int maxTicks ) with(potato) { |
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| 41 | if ( maxTicks < 2 ) abort( "Hot Potato initialized with less than 2 ticks" ); // optional |
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| 42 | deadline = prng( prng, 1, maxTicks ); |
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| 43 | timer = 0; |
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| 44 | sout | " POTATO goes off after " | deadline | " tick" | nosep | (deadline > 1 ? "s" : ""); |
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| 45 | } // reset |
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| 46 | |
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| 47 | void countdown( Potato & potato ) with(potato) { |
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| 48 | timer += 1; |
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[26be854] | 49 | if ( timer == deadline ) throwResume ExceptionInst( Explode ); |
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[fd775ae] | 50 | } // countdown |
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| 51 | |
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| 52 | static unsigned int rightOf( unsigned int me, unsigned int total ) { |
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| 53 | return ( me + 1 ) % total; |
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| 54 | } // rightOf |
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| 55 | |
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| 56 | static unsigned int leftOf( unsigned int me, unsigned int total ) { |
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| 57 | return ( me + total - 1) % total; |
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| 58 | } // leftOf |
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| 59 | |
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| 60 | enum { LEFT = 0, RIGHT = 1 }; |
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| 61 | |
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| 62 | static void vote( Player & player, Election & election ) { // cause partner to vote |
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| 63 | resumeAt( player, election ); |
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| 64 | resume( player ); |
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| 65 | } // vote |
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| 66 | |
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| 67 | void init( Player & player, Player & lp, Player & rp ) with(player) { // supply partners |
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| 68 | partner[LEFT] = &lp; |
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| 69 | partner[RIGHT] = &rp; |
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| 70 | resume( player ); // establish main as starter for termination |
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| 71 | } // init |
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| 72 | |
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| 73 | int getId( Player & player ) { // player id |
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| 74 | return player.id; |
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| 75 | } // getId |
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| 76 | |
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| 77 | void main( Player & player ) with(player) { |
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| 78 | suspend; // return immediately after establishing starter |
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| 79 | try { |
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| 80 | for ( ;; ) { |
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| 81 | poll(); // check for non-local exceptions before proceeding |
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| 82 | |
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| 83 | if ( partner[LEFT] == &player ) { // stop when only one player |
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| 84 | sout | id | " wins the Match!"; |
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[26be854] | 85 | return; |
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[fd775ae] | 86 | } // exit |
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| 87 | |
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| 88 | countdown( potato ); // player is eliminated if countdown() returned true |
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| 89 | |
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| 90 | size_t side = prng( prng, 2 ); |
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| 91 | sout | id | " -> " | nonl; |
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[7a925a41] | 92 | resume( *partner[ side ] ); // random toss left/right |
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[fd775ae] | 93 | } // for |
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| 94 | } catchResume( Terminate * v ) { |
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| 95 | v->victim->partner[LEFT]->partner[RIGHT] = v->victim->partner[RIGHT]; // unlink node |
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| 96 | v->victim->partner[RIGHT]->partner[LEFT] = v->victim->partner[LEFT]; |
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| 97 | delete( v->victim ); |
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| 98 | reset( potato ); |
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| 99 | sout | "U " | nonl; // start new game |
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| 100 | flush( sout ); |
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| 101 | } catchResume( Election * election ) { |
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| 102 | sout | "election"; |
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| 103 | sout | " -> " | id | nonl; |
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[26be854] | 104 | if ( id > getId( umpire ) ) &umpire = &player; // set umpire to highest id so far |
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[fd775ae] | 105 | vote( *partner[RIGHT], *election ); |
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[26be854] | 106 | } catchResume ( Explode * ) { |
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[fd775ae] | 107 | sout | id | " is eliminated"; |
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| 108 | if ( &player == &umpire ) { |
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| 109 | id = -1; // remove from election |
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[26be854] | 110 | vote( *partner[RIGHT], ExceptionInst( Election ) ); // start election |
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| 111 | try { poll(); } catchResume( Election * election ) {} // handle end of election |
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| 112 | sout | " : umpire " | getId( umpire ); |
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[fd775ae] | 113 | } // if |
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| 114 | resumeAt( umpire, ExceptionInst( Terminate, &player ) ); |
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[7a925a41] | 115 | resume( umpire ); // resume umpire to terminate this player |
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[fd775ae] | 116 | assert( false ); // no return |
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| 117 | } // try |
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| 118 | } // main |
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| 119 | |
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| 120 | |
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| 121 | int main( int argc, char * argv[] ) { |
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| 122 | enum { |
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| 123 | MinNoPlayers = 2, // minimum players in the game |
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| 124 | MaxNoPlayers = 10, // maximum players in the game |
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| 125 | DefaultGames = 5, // default games to play |
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| 126 | }; |
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| 127 | intmax_t numGames = DefaultGames; // games to play |
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| 128 | intmax_t numPlayers = 0; // players for a particular game |
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| 129 | intmax_t seed = 42; // random-number seed |
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| 130 | bool playersSet = false; |
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| 131 | char * nosummary = getenv( "NOSUMMARY" ); // print extra output |
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| 132 | |
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| 133 | try { |
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| 134 | choose ( argc ) { |
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| 135 | case 4: |
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| 136 | if ( strcmp( argv[3], "d" ) != 0 ) { // default ? |
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| 137 | seed = convert( argv[3] ); if ( seed < 1 ) throw ExceptionInst( cmd_error ); // invalid ? |
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| 138 | } // if |
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| 139 | fallthrough; |
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| 140 | case 3: |
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| 141 | if ( strcmp( argv[2], "d" ) != 0 ) { // default ? |
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| 142 | numPlayers = convert( argv[2] ); if ( numPlayers < 2 ) throw ExceptionInst( cmd_error ); // invalid ? |
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| 143 | playersSet = true; |
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| 144 | } // if |
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| 145 | fallthrough; |
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| 146 | case 2: |
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| 147 | if ( strcmp( argv[1], "d" ) != 0 ) { // default ? |
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| 148 | numGames = convert( argv[1] ); if ( numGames < 0 ) throw ExceptionInst( cmd_error ); // invalid ? |
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| 149 | } // if |
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| 150 | fallthrough; |
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| 151 | case 1: ; // defaults |
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| 152 | default: // too many arguments |
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| 153 | throw ExceptionInst( cmd_error ); |
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| 154 | } // choose |
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| 155 | } catch( exception_t * ) { // catch any |
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| 156 | exit | "Usage: " | argv[0] |
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| 157 | | " [ games (>=0) | 'd' (default " | DefaultGames |
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| 158 | | ") [ players (>=2) | 'd' (random " | MinNoPlayers | "-" | MaxNoPlayers |
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| 159 | | ") [ seed (>0) | 'd' (random) ] ] ]"; |
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| 160 | } // try |
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| 161 | sout | numGames | numPlayers | seed; |
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| 162 | |
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| 163 | PRNG mprng, hprng, pprng; |
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| 164 | if ( seed != 0 ) { // specified on command line ? |
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| 165 | set_seed( mprng, seed ); set_seed( hprng, seed ); set_seed( pprng, seed ); |
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| 166 | } // if |
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| 167 | |
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| 168 | for ( game; 1 ~= numGames ) { |
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| 169 | if ( ! playersSet ) numPlayers = prng( mprng, MinNoPlayers, MaxNoPlayers ); |
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| 170 | sout | numPlayers | " players in the game"; |
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| 171 | { |
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| 172 | Potato potato{ hprng }; // hot potato to be tossed |
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| 173 | Player * players[numPlayers]; |
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| 174 | |
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| 175 | for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) { // start the players |
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| 176 | players[i] = malloc(); |
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| 177 | ?{}( *players[i], pprng, i, potato ); |
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| 178 | } // for |
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| 179 | |
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| 180 | // Do not swap player[0] with itself. |
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| 181 | unsigned int rposn = prng( mprng, 1, numPlayers - 1 ); // swap random position with 0 |
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| 182 | swap( players[0], players[rposn] ); |
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| 183 | |
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| 184 | // Tell each player its partner. |
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| 185 | for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) { |
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| 186 | init( *players[i], *players[leftOf(i, numPlayers)], *players[rightOf(i, numPlayers)] ); |
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| 187 | } // for |
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| 188 | |
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| 189 | &umpire = players[rposn]; // designate umpire and start game |
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| 190 | sout | "U " | nonl; |
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[7a925a41] | 191 | resume( *players[rposn] ); |
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[fd775ae] | 192 | delete( &umpire ); |
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| 193 | } |
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| 194 | if ( game < (unsigned int)numGames ) sout | nl | nl; // whitespace between games |
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| 195 | } // for |
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| 196 | } // main |
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| 197 | |
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| 198 | // Local Variables: // |
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| 199 | // compile-command: "make hotpotato" // |
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| 200 | // End: // |
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