124.求二维数组周边元素之和

函数fun功能是：求出二维数组周边元素之和，作为函数值返回，二维数组中的值在主函数中赋予。

#define _CRT_SECURE_NO_WARNINGS 
#include<stdio.h>
#define M 4
#define N 5
int fun(int a[M][N])
{
	int i, s = 0;
	for (i = 0;i < N;i++)
		s += a[0][i] + a[M - 1][i];
	for (i = 1;i < M - 1;i++)
		s += a[i][0] + a[i][N - 1];
	return s;
}
int main()
{
	int aa[M][N] = { {1,3,5,7,9},{2,9,9,9,4},{6,9,9,9,8},{1,3,5,7,0} };
	int i, j, y;
	printf("The original data is:
");
	for (i = 0;i < M;i++)
	{
		for (j = 0;j < N;j++)
			printf("%6d", aa[i][j]);
		printf("
");
	}
	y = fun(aa);
	printf("
The sun:%d
", y);
	printf("
");
	system("pause");
	return 0;
}