UVA 10341 Solve It 解方程 二分查找+精度

题意：给出一个式子以及里面的常量，求出范围为[0,1]的解，精度要求为小数点后4为。

二分暴力查找即可。

e^(-n)可以用math.h里面的exp(-n)表示。

代码：（uva该题我老是出现Submission Error，过几天再试看看）

/*
*   Author:        illuz <iilluzen@gmail.com>
*   Blog:          http://blog.csdn.net/hcbbt *   File:          uva10241.cpp
*   Lauguage:      C/C++
*   Create Date:   2013-08-25 15:37:46
*   Descripton:    UVA 10341 Solve It,  bisection
*/
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <list>
#include <vector>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <utility>
#include <algorithm>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define repu(i, a, b) for (int i = (a); i < (b); i++)
#define repf(i, a, b) for (int i = (a); i <= (b); i++)
#define repd(i, a, b) for (int i = (a); i >= (b); i--)
#define swap(a, b) {int t = a; a = b; b = t;}
#define mc(a) memset(a, 0, sizeof(a))
#define ms(a, i) memset(a, i, sizeof(a))
#define sqr(x) ((x) * (x))
#define FI(i, x) for (typeof((x).begin()) i = (x).begin(); i != (x).end(); i++)
typedef long long LL;
typedef unsigned long long ULL;

/****** TEMPLATE ENDS ******/

double p, q, r, s, t, u;

#define calc(x) (p*exp(-x)+q*sin(x)+r*cos(x)+s*tan(x)+t*x*x+u)

int main() {
while (scanf("%lf%lf%lf%lf%lf%lf", &p, &q, &r, &s, &t, &u)) {
if (calc(0) < 0 || calc(1) > 0) printf("No solution\n");
else {
double x1 = 0, x2 = 1;
while (abs(x1 - x2) >= 1e-10) {
double x = (x1 + x2) / 2.0;
if (calc(x) > 0) x1 = x;
else x2 = x;
}
printf("%.4lf\n", x1);
}
}
return 0;
}