c - 随机数组选择

Question

我正在做一个井字棋(没有矩阵)，我对此有疑问。

假设我在这里输入的是“5”:

printf(" 1 | 2 | 3 \n");
printf("___|___|___\n");
printf(" 4 | 5 | 6 \n");
printf("___|___|___\n");
printf(" 7 | 8 | 9 \n");
printf("   |   |   \n");
printf("\n");

我希望 A.I.选择一个随机框，不包括我输入的“5”。我正在做随机的事情:

srand ( time(NULL) );
int randIndex = rand() % 8; 
    if (movement == 5 && i == 0){
            xslot[randIndex] = 'O';
            steps = 1;
    } 

我不知道如何从这个随机选择中排除“5”。

这是我的数组:

char xslot[] = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};

谢谢

编辑:完整代码:

main()
{
    int movimento,passos;
    bool passo1=false,passo2=false,passo3=false,passo4=false,passo5=false;
    char oslot[9] = "O";    
    char xslot[] = {'1', '2', '3', '4', '5', '6', '7', '8', '9'};
    srand ( time(NULL) );

    printf("\n\n");

    printf(" 1 | 2 | 3 \n");
    printf("___|___|___\n");
    printf(" 4 | 5 | 6 \n");
    printf("___|___|___\n");
    printf(" 7 | 8 | 9 \n");
    printf("   |   |   \n");
    printf("\n");

    printf("Digite o numero do seu movimento:");
    for(int i =0;i<5;i++){
        scanf("%i",&movimento);

            if (movimento == 1){
                xslot[0] = 'X';
            } else if (movimento == 2){
                xslot[1] = 'X';
            } else if (movimento == 3){
                xslot[2] = 'X';
            } else if (movimento == 4){
                xslot[3] = 'X';
            } else if (movimento == 5){
                xslot[4] = 'X';
            } else if (movimento == 6){
                xslot[5] = 'X';
            } else if (movimento == 7){
                xslot[6] = 'X';
            } else if (movimento == 8){
                xslot[7] = 'X';
            } else if (movimento == 9){
                xslot[8] = 'X';
            }   

            //INTELIGENCIA ARTIFICIAL

            int randIndex = rand() % 8;

            if (movimento == 5 && i == 0){
                    xslot[randIndex] = 'O';
                    passos = 1;
            } 

Answer 1

使用包含可用选择的数组，并在每次选择选择时“缩小”它:

size_t numSelections = 9;
int selections [] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
while (numSelections > 0) {
  size_t const next = rand() % numSelections;
  --numSelections;
  // move selected selection out of valid array range
  int const selection = selections [next];
  selections [next] = selections [numSelections];
  printf("Selected %d\n", selection);
}

Live demo

每次选择一个值时，都会将其移出数组的有效范围，并将该值(未选择，但现在超出范围)移回到有效的数组范围内:

1 2 3 4|
;; select the 3, shrink valid range
1 2 3|4
;; move 3 out, bring 4 back in
1 2 4|x

在上面的示例中，选择是随机发生的，但您可以轻松修改它 - 例如 - 在随机选择和用户定向选择之间交替来实现您的游戏