c/c++语言开发共享洛谷P1024 一元三次方程求解(数学)

题意

题目链接

sol

本来是一道好的公式题。

然后输出只要保留两位小数？？

直接上不就赢了嘛。。

#include<bits/stdc++.h> #define ll long long using namespace std; const int maxn = 1e6; const double eps = 1e-3; inline int read() {     char c = getchar(); int x = 0, f = 1;     while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}     while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();     return x * f; } double a, b, c, d; int tot = 0; bool dcmp(double x) {     return fabs(x) <= eps; } void check(double k) {     if(dcmp(a * k * k * k + b * k * k + c * k + d)) printf("%.2lf ", k), tot++; } int main() {     scanf("%lf%lf%lf%lf", &a, &b, &c, &d);     for(double i = -100; i <= 100; i += 0.01) {         check(i);         if(tot == 3) break;     }     return 0;  }