第一次实验

1.#include<stdio.h>
int main(){
 int a,b,sum;
 a = 123;
 b = 456;
 sum = a + b;
 printf("sum is %d\n",sum);
 return 0;
}

2.#include<stdio.h>
int main()
{
 char c1,c2;
 c1 = 97;
 c2 = 98;
 printf("c1 = %c,c2 = %c\n",c1,c2);
 printf("c2 = %d,c2 = %d\n",c1,c2);
 return 0;
}

3.#include<stdio.h>
#include<math.h>
int main()
{
 double x,y,z;
 scanf("%lf %lf",&x,&y);
 z = x + 1.0/fabs(y);
 printf("%d,%15.6f,%e",(int)z,z,z);
 return 0;
}