在C中的二维数组中查找Kaprekar数

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define ROWS 3
#define COLS 3

void findKaprekarNumbers(int arr[ROWS][COLS]) {
    int kaprekarNumbers[ROWS*COLS]; // 存储找到的Kaprekar数
    int count = 0; // 计数器，记录找到的Kaprekar数的个数

    for (int i = 0; i < ROWS; i++) {
        for (int j = 0; j < COLS; j++) {
            int num = arr[i][j];
            int square = num * num;
            char str[20];
            sprintf(str, "%d", square);

            int len = strlen(str);
            int mid = len / 2;

            int left = atoi(strncpy(str, str, mid));
            int right = atoi(strncpy(str, str + mid, len - mid));

            if (left + right == num) {
                kaprekarNumbers[count] = num;
                count++;
            }
        }
    }

    printf("找到的Kaprekar数：\n");
    for (int i = 0; i < count; i++) {
        printf("%d ", kaprekarNumbers[i]);
    }
    printf("\n");
}

int main() {
    int arr[ROWS][COLS] = {
        {1, 9, 45},
        {55, 99, 297},
        {703, 999, 2223}
    };

    findKaprekarNumbers(arr);

    return 0;
}