C语言-全排列

//打印数组元素
void printfArray(int a[], int num) {
    for (int i = 0; i < num; ++i) {
        printf("%d", a[i]);
    }
    printf("\n");
}

//数组元素交换
void swap(int a[], int i, int j) {
    int temp = a[i];
    a[i] = a[j];
    a[j] = temp;
}

//参数列表：数组 全排列的起始下标 结束下标 数组元素个数
void full_Permutation(int a[], int startIndex, int endIndex, int num) {
    if (startIndex == endIndex) {
        printfArray(a, num);
    } else {
        for (int i = startIndex; i <= endIndex; ++i) {
            swap(a, startIndex, i);
            full_Permutation(a, startIndex + 1, endIndex, num);
            swap(a, startIndex, i);
        }
    }
}

//参数列表：数组 数组元素个数
void fullPermutation(int a[], int num) {
    full_Permutation(a, 0, num - 1, num);
}

//调用示例
int main() {
    int a[] = {1, 2, 3};
    fullPermutation(a, 3);
    return 0;
}