#include<stdio.h>
main()
{
    float math,english,computer,sum,average;
    sum=0;
    printf("math=75,english=89,computer=91:\n");
    scanf("%If%If%If",&math,&english,&computer);
    sum=math+english+computer;
    average=sum\3;
    printf("sum=%.2f average=%.2f\n",sum,average);
}
D:\Microsoft Visual Studio\MyProjects\rin1\rin1.c(9) : error C2017: illegal escape sequence
D:\Microsoft Visual Studio\MyProjects\rin1\rin1.c(9) : error C2143: syntax error : missing ';' before 'constant'
执行 cl.exe 时出错.

谢谢，但是你知道为什么输出结果是负数，而且很大么?求解