c语言求数组差集的程序

以下是一个用C语言实现求两个数组差集的程序：

#include <stdio.h>

int main() {
    int arr1[] = {1, 2, 3, 4, 5};
    int arr2[] = {3, 4, 5, 6, 7};
    int len1 = sizeof(arr1) / sizeof(arr1[0]);
    int len2 = sizeof(arr2) / sizeof(arr2[0]);
    int i, j, k, flag;

    printf("Array1: ");
    for (i = 0; i < len1; i++) {
        printf("%d ", arr1[i]);
    }
    printf("\n");

    printf("Array2: ");
    for (i = 0; i < len2; i++) {
        printf("%d ", arr2[i]);
    }
    printf("\n");

    printf("Difference: ");    for (i = 0; i < len1; i++) {
        flag = 0;
        for (j = 0; j < len2; j++) {
            if (arr1[i] == arr2[j]) {
                flag = 1;
                break;
            }
        }
        if (flag == 0) {
            printf("%d ", arr1[i]);
        }
    }
    printf("\n");

    return 0;
}

运行结果为：

Array1: 1 2 3 4 5 
Array2: 3 4 5 6 7 
Difference: 1 2