PAT1051

#include<iostream>#include <math.h>using namespace std;int main() {    double r1, p1, r2, p2;    double a, b;    cin >> r1 >> p1 >> r2 >> p2;        a = (r1*r2)*cos(p1 + p2);    b = (r1*r2)*sin(p1 + p2);    if (-0.005<a&&a<0) a=0;    if (-0.005<b&&b<0) b = 0;    if(b>=0) printf("%.2f+%.2fi", a, b);    else printf("%.2f%.2fi", a, b);    return 0;}

1. cos和sin函数定义在math.h
2. 不存在负0