Problem Description

Bessie is traveling on a road teeming with interesting landmarks. The road is labeled just like a number line, and Bessie starts at the "origin" (x = 0). A total of N (1 ≤ N ≤ 50,000) landmarks are located at points x1, x2, ..., xN (-100,000 ≤ xi ≤ 100,000). Bessie wants to visit as many landmarks as possible before sundown, which occurs in T (1 ≤ T ≤ 1,000,000,000) minutes. She travels 1 distance unit in 1 minute.

Bessie will visit the landmarks in a particular order. Since the landmarks closer to the origin are more important to Farmer John, she always heads for the unvisited landmark closest to the origin. No two landmarks will be the same distance away from the origin.
Help Bessie determine the maximum number of landmarks she can visit before the day ends.

Input

Line 1: Two space-separated integers: T and N

Lines 2..N+1: Line i+1 contains a single integer that is the location of the ith landmark: xi

Output

Line 1: The maximum number of landmarks Bessie can visit.

Sample Input

25 5

10
-3
8
-7
1

Sample Output

4

題意：一條數(shù)軸上，給n個(gè)點(diǎn)，從原點(diǎn)出發(fā)，優(yōu)先達(dá)到距離原點(diǎn)最近的點(diǎn)，求t秒內(nèi)到達(dá)的點(diǎn)的最大數(shù)量。

思路：點(diǎn)的坐標(biāo)有正有負(fù)，升序排序時(shí)按絕對(duì)值大小排序，然后計(jì)算t秒內(nèi)到達(dá)的最大數(shù)量即可。

Source Program

#include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> #include<string> #include<cstdlib> #include<queue> #include<vector> #define INF 0x3f3f3f3f #define PI acos(-1.0) #define N 100001 #define MOD 2520 #define E 1e-12 using namespace std; int a[N]; bool cmp(int x,int y) {return abs(x)<abs(y); } int main() {int t,n;scanf("%d%d",&t,&n);for(int i=1;i<=n;i++)scanf("%d",&a[i]);sort(a+1,a+1+n,cmp);int cnt=0;int use=0;//已用時(shí)間int k=1;if(a[1]==0){cnt=1;k++;}for(int i=k;i<=n;i++){int time=abs(a[i]-a[i-1]);if(time<=t-use)//若時(shí)間足夠，則前往下一點(diǎn){cnt++;use+=time;//累計(jì)已用時(shí)間}elsebreak;}printf("%d\n",cnt);return 0; }

?

總結(jié)

以上是生活随笔為你收集整理的Exploration（POJ-3618）的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問(wèn)題。

如果覺(jué)得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。