题目链接:点击打开链接

题意:

给定n个加油站,一辆车由A点跑到B点,每个100m有一个加油站,每开100m需要10升油。

在每个车站会检查一下油量,若车子若开不到下一个加油站则加x升油。

开始有x升油

下面给出加油的记录。

问下一次加油在哪一站。若答案唯一输出具体哪站。

油箱容量无限

思路:

水模拟。。

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <iostream>
using namespace std;
#define gg 10.0
#define N 1005
#define eps (1e-6)
#define ll int
double p[N];
ll n;
void input(){
	for(ll i = 1; i <= n; i++)cin>>p[i];
}
double ok(double x){
	double now = x;
	double siz = 0;
	for(ll i = 1; i <= n; i++)
	{		
		siz += floor(now/gg);
		now -= floor(now/gg)*gg;
		if(siz != p[i]){
			double cha = (p[i] - siz)*10.0 - now;
			now = 0;
			x += cha / i;
		}
		siz = p[i];
		now += x;
	}
	return now;
}
double ok2(double x){
	double now = x;
	double siz = 0;
	for(ll i = 1; i <= n; i++)
	{		
		siz += floor(now/gg);
		now -= floor(now/gg)*gg;
		if(siz != p[i]){
			double cha = (siz - p[i])*10.0 - (10.0-now-eps);
			now = 10.0 - eps;
			x -= cha / i;
		}
		siz = p[i];
		now += x;
	}
	return now;
}
int main(){
	ll i, j;
	while(cin>>n){
		input();
		double l = ok(p[1]*10.0) + eps;
		double r = ok2(p[1]*10.0 + 10.0);
		l = floor(l/10.0);
		r = floor(r/10.0);
		if(l == r)
		{
			puts("unique");
			printf("%.0lf\n", p[n] + l);
		}
		else puts("not unique");
	}
	return 0;
}