Practice 7-7 matrix operation (20 points)

practice 7-7 Matrix operations (20 branch )

Given a n×n Matrix of , This problem requires the calculation of the matrix divided by the sub diagonal 、 The sum of all elements except the last column and the last row . The sub diagonal is the line from the upper right corner of the matrix to the lower left corner .

Input format :

Enter the first line to give a positive integer n（1<n≤10）; And then n That's ok , Each line gives n It's an integer , Separated by spaces .

Output format :

Give the matrix in one row divided by the sub diagonal 、 The sum of all elements except the last column and the last row .

sample input :

4
2 3 4 1
5 6 1 1
7 1 8 1
1 1 1 1

No blank lines at the end

sample output :

35

No blank lines at the end

#include <stdio.h>
int main()
{
    int n,i,j;
    scanf("%d",&n);
    const int max=n;
    int a[max][max],sum=0;
    for (i=0;i<max;i++) {
        for (j=0;j<max;j++) {
            scanf("%d",&a[i][j]);
            sum+=a[i][j];   
        }
    }
    int sum1=0,sum2=0,sum3=0;
    for (i=0;i<max;i++) {
        sum1+=a[n-1][i];
        sum2+=a[i][n-1];
        sum3+=a[i][n-1-i];
    }
    printf("%d",sum-sum1-sum2-sum3+a[n-1][n-1]+a[n-1][0]+a[0][n-1]);
}