C语言改变数组中元素的值

Question

一旦我的程序在我的代码中执行到这个函数，我的程序就会崩溃。我打印了正在进入的函数中的数组，并注释掉了其他所有内容，然后 他们正在正确通过。我不明白为什么它会在这里崩溃。

数组是按升序排列的数字。
也许我的循环或 if 语句不正确？我想当它到达 attackerArmy[d] = '0' 时，我可能没有正确更改数组中索引“d”处的值；//代表 0 被打败了 ?

long int defeatedArmies(long int* attackerArmy, long int* defenderArmy, long int size){

    long int i,j,defeated = 0,d;

    for(i=0;i<size;i++){
        for(j=0;j<size;j++){

        //loop for the highest attack value that is lower than defender
            if(attackerArmy[j] < defenderArmy[i])
                d = j; // save the index where it is highest

            if(attackerArmy[j] > defenderArmy[i])
            //no point in checking unnecessary values
                break;
        }
        attackerArmy[d] = '0'; //represent 0 as defeated
    }

    for(i=0;i<size;i++){
        if(attackerArmy[i] == 0) //count how many defeated armies happened
            defeated++;
    }
return defeated;
}

Answer 1

问题
如果 attackerArmy[j] >= defenderArmy[i] 为真，d 保持未初始化状态，当您在 attackerArmy[d] = ' 中访问它的值时会导致未定义的行为0';.

可能的修复
声明时初始化 d。

例如:

long int d = -1L;
...
if(d != -1L) attackerArmy[d] = '0';