怎么全输出300.0啊

#include <iostream>
#include <cstdio>
using namespace std;
int w0,w,m;
bool check(double x){
    double a = w0;
    for (int i = 1;i <= m;i++){
        a *= (1 + x);
        a -= w;
    }
    return a <= 0;
}
int main(){
    int w0,w,m;
    cin >> w0 >> w >> m;
    double l = 0.001,r = 3;
    for (int i = 1;i <= 114514;i++){
        double mid = (l + r) / 2;
        if (check(mid)) l = mid;
        else r = mid;
    }
    printf("%.1f",l * 100);
    return 0;
}