c语言：1.写两个函数，子函数中完成两个整数的和，在主函数中输出。

#include "stdio.h"
int he(int a,int b)
{int c;
c=a+b;
return c;
}
void main()

{

int iFirstNum,iSecondNum,iSum;

iFirstNum=10;

iSecondNum=20;

iSum=he(iFirstNum,iSecondNum);

printf("%d+%d=%d",iFirstNum,iSecondNum,iSum);

}

#include <stdio.h>
int main(){
int sum(int, int);
int operand1, operand2;
printf("Please key in two integers:\n");
scanf("%d,%d", &operand1,&operand2);
printf("The sum of the two integers is %d\n",sum(operand1,operand2));
return 0;
}
int sum(int a, int b){
return a + b;
}