大佬们看看我这个计算Π的近似值为啥没有输出，好像是死循环了但是不知道问题出现在哪儿！

Question

#include <iostream>
#include <cmath>
using namespace std;
int main(){
    double pi = 0.0,term = 1.0,sign = 1.0,sum = 0.0;
    double limit = pow(10,-6);
    while(fabs(term)>limit){
        sum += term;
        sign = -sign;
        term = term + 2;
        term = (sign/term);
    }
    pi = 4*term;
    cout<<pi<<endl;
    return 0;
}

Answer 1

 term = term + 2;
 term = (sign/term);

你这里搞错了，term = (sign/term); 执行这个以后，term为分数，再term = term + 2，就不对了，应该分母加2；

下面我稍稍改了下，运行结果正常；

#include <iostream>
#include <cmath>
using namespace std;
int main(){
    double pi = 0.0,term = 1.0,sign = 1.0,sum = 0.0;
    double limit = pow(10,-6);

    double item = term;
    while(fabs(item)>limit){ //pi/4=1-1/3+1/5-1/7......
        sum += item;
        sign = -sign;
        term = term + 2;
        item = (sign/term);
    }
    pi = 4*sum;
    cout<<pi<<endl;
    return 0;
}