注意事项:因为要求保留两位小数,所以用double定义,输入和输出时都用%lf 参考代码: #include <stdio.h> #include <stdlib.h> int main() { double a,b,c,sum,i,sum1,sum2,sum3; scanf("%lf %lf %lf",&a,&b,&c); for(i=1;i<=a;i++){sum1 += i;} for(i=1;i<=b;i++){sum2 +=...