看程序,写出运行结果 #include <stdio. h> int sum(int a, int b) i a=a+b; b=a+b; return a; void maino Sum of 1. 3 is 4 int a=1.b=3.c: c=sum(a, b) printf(sum of %d, d is %d \n, a, b, c);看程序，写出运行结果 #include <stdio.h> int sum(int a,int b) { a=a+b; b=a+b; return a; } void main() { int a=1,b=3,c; c=sum(a,b); printf(“sum of %d,%d is %d\n”,a,b,c); } Sum of 1,3 is 4