题解 | #求解立方根#

#include <cstdio>
double abs(double n) {
    if(n < 0) {
        return -n;
    }
    return n;
}
double cube(double n) {
    return n * n * n;
}
double compute(double n) {
    double left, right, mid;
    if(n > 1) {
        left = 1;
        right = n;
    } else {
        left = 0;
        right = 1;
    }
    while(abs(left - right) > 0.001) {
        mid = (left + right) / 2;
        if(cube(mid) > n) {
            right = mid;
        } else {
            left = mid;
        }
    }
    return mid;
}
int main() {
    double n;
    while(EOF != scanf("%lf", &n)) {
        if(n < 0) {
            n = -n;
            printf("-");
        }
        printf("%.1lf\n", compute(n));
    }
}