c语言数组问题。，。，

#include <stdio.h>
#include<string.h>
#include<stdlib.h>
int main()
{
    int a[4][4], b[4][4];
    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            scanf("%d", &a[i][j]);
    for (int i = 0; i < 4; i++)
        b[0][i] = a[3][i];
    for (int i = 0; i < 3; i++)
    {
        for (int j = 0; j < 4; j++)
            b[i + 1][j] = a[i][j];
    }
    for (int i = 0; i < 4; i++)
    {
        for (int j = 0; j < 4; j++)
        {
            printf("%d ", b[i][j]);
        } 
        printf("\n");
    }
    return 0;
}