c - 在递归函数中修改二维数组，C

Question

我正在尝试递归修改 2D char 数组(字符串数组)，但在第一次递归调用后，即使更改在基本情况下注册，数组仍返回空白

int main(int argc, const char * argv[]) {

int height;
printf("Enter the height of your triangle.\n");
scanf("%d", &height);


printf("Lets see if you were successful!\n");
fractalTriangle(height, 1);

}

void fractalTriangle (int height, int fractalLevel) {

//has to make the array and do the printing all in the same function
char trianglePattern [height][2 * height - 1];

if (fractalLevel == 0) {
    int rowSize = 2 * height - 1;
    char rowString[rowSize]; //string to store in pattern's array
    int asteriskCount = 1; //number of asterisks printed in each row
    int spaces = (rowSize - asteriskCount) / 2; //how many spaces need to be printed in this current row

    int rowCount;
    for (rowCount = 0; rowCount < height; rowCount++) {
        char *ptr = trianglePattern[rowCount];
        int counter = 0;
        int astCounter = 0;
        int spCounter = 0;

        while (spCounter < spaces) {
            if (counter == 0) {
                strcpy(rowString, " ");
            }
            else {
                strcat(rowString, " ");
            }
            counter++;
            spCounter++;
        }

        while (astCounter < asteriskCount) {
            if (counter == 0) {
                strcpy(rowString, "*");
            }
            else {
                strcat(rowString, "*");
            }
            counter++;
            astCounter++;
        }

        spCounter = 0;
        while (spCounter < spaces) {
            strcat(rowString, " ");
            spCounter++;
        }

        asteriskCount+=2;
        spaces--;
        strcpy(ptr, rowString);
        //printf("%s\n", trianglePattern[rowCount]);
        //printf("%s\n", rowString);
    }
}

else {
    fractalTriangle(height/2, fractalLevel - 1);
    printf("%s\n", trianglePattern[0]);
    printf("%s\n", trianglePattern[1]);
    printf("%s\n", trianglePattern[2]);
    printf("%s\n", trianglePattern[3]);

}

为什么阵列会重置？我无法想象这会是一个范围问题，因为数组本身是在函数中声明的。目的是打印分形三角形，因此无需将二维数组传递给函数，我只想递归地创建图案。我正在一点一点地做这件事(递归仍然不完整)——现在我只是在测试以查看数组是否从调用到调用保持不变。

Answer 1

由于您在函数范围内定义数组，每个函数都会在堆栈上创建一个新的二维字符数组。该函数将仅对二维字符数组的那个 实例进行操作。到递归存在时，打印原始未修改的二维字符数组。

您需要在递归函数之外定义一个字符数组，然后将该字符数组(或者更确切地说是指向它的指针)传递给递归函数。