c# - Negamax for simple addition game -

i'm trying implement negamax simple game players alternate adding 1 or 2 running sum. player increases total 21 wins.

i'm using pseudocode here: https://en.wikipedia.org/wiki/negamax#negamax_base_algorithm

the human player moves first computer should win adding number makes total congruent 0 mod 3.

i'm not doing dynamic move generation. comparing negamax score adding 1 running sum negamax score adding 2 running sum.

int total = 0;  console.writeline("the current total " + total);  while (total < 21) {     console.writeline("add 1 or 2?");     total += convert.toint32(console.readline());     console.writeline("you increased total " + total);     if (total == 21) {         console.writeline("you win");         break;     }      if (negamax(total + 1, 1) > negamax(total + 2, 1)) total++;     else total += 2;      console.writeline("computer increased total " + total);     if (total == 21) {         console.writeline("computer wins");         break;     } } 

the negamax function:

static int negamax(int total, int color) {     if (total == 21) {         return color * 100;     }      int bestvalue = -100;      (int = 1; <= 2; i++) {         if (total + <= 21) {             int v = -1 * negamax(total + i, -1 * color);             bestvalue = max(bestvalue, v);         }     }     return bestvalue; } 

max method:

static int max(int a, int b) {     if (a > b) return a;     return b; } 

not sure why ai adding 2 every time.

the static evaluation function incorrect.

https://en.wikipedia.org/wiki/negamax#negamax_base_algorithm negamax node's return value heuristic score from point of view of node's current player.

if (total == 21), it's loss node's current player. negamax return must -100. there other code errors too, such when total 22.