习题4

4.1

(1)

#include <stdio.h>#include <stdlib.h>int main(){    char c1='a',c2='b',c3='c';    printf ("a%cb%cc%c\n",c1,c2,c3);    return 0;}

(2)

#include <stdio.h>#include <stdlib.h>int main(){    int a=12,b=15;    printf("a=%d%%,b=%d%%\n",a,b);    return 0;

}

(3)
#include <stdio.h>#include <stdlib.h>int main(){    int a,b;    scanf("%2d%*2s%2d",&a,&b);    printf("%d,%d\n",a,b);    return 0;}
4.2
#include <stdio.h>#include <stdlib.h>int main(){    long a,b;    float x,y;    scanf("%d,%d\n",&a,&b);    scanf("% 5.2f,%5.2f\n",&x,&y);    printf("a=%d,b=%d\n",a,b);    printf("x=%d,y=%d\n",x,y);    return 0;}