Question

用指针和函数求一个3*3矩阵对角线元素之和

Answer 1

#include "stdio.h"
#include "time.h"
#include "stdlib.h"
void inita(int a[3][3]){
srand((unsigned int)time(NULL));
int i,j;
for(i=0;i<3;i++){
for(j=0;j<3;j++){
a[i][j]=rand()%101;
printf("%5d",a[i][j]);
}
printf("\n\n");
}
}
void sum(int a[3][3],int &sum1,int &sum2){
int i,j;
for(i=0;i<3;i++){
for(j=0;j<3;j++){
if(i==j)
sum1+=a[i][j];
if(i+j==2)
sum2+=a[i][j];
}
}
}
void main(){
int a[3][3],sum1=0,sum2=0;
inita(a);
sum(a,sum1,sum2);
printf("其中主对角线元素之和为：%5d\n副对角线元素之和为：%5d\n\n",sum1,sum2);
}