标签：最大值 show ace line each include gets pos ide
Alex doesn‘t like boredom. That‘s why whenever he gets bored, he comes up with games. One long winter evening he came up with a game and decided to play it.
Given a sequence a consisting of n integers. The player can make several steps. In a single step he can choose an element of the sequence (let‘s denote it ak) and delete it, at that all elements equal to ak?+?1 and ak?-?1 also must be deleted from the sequence. That step brings ak points to the player.
Alex is a perfectionist, so he decided to get as many points as possible. Help him.
Input
The first line contains integer n (1?≤?n?≤?105) that shows how many numbers are in Alex‘s sequence.
The second line contains n integers a1, a2, ..., an (1?≤?ai?≤?105).
Output
Print a single integer — the maximum number of points that Alex can earn.
Example
2
1 2
2
3
1 2 3
4
9
1 2 1 3 2 2 2 2 3
10
Note
Consider the third test example. At first step we need to choose any element equal to 2. After that step our sequence looks like this [2,?2,?2,?2]. Then we do 4 steps, on each step we choose any element equals to 2. In total we earn 10 points.
维护两个变量，即b（包含上一个的最大值），c（不包含上一个的最大值）。
#include<iostream> #include<cstdio> #include<algorithm> #include<cmath> #define lld I64d using namespace std; long long d[100005]; int main() { long long a=0,b=0,c,x; int n; scanf("%d",&n); for(int i=0;i<n;i++) { scanf("%lld",&x); d[x]+=x; } for(int i=1;i<=100000;i++) { c=a+d[i]; a=max(a,b); b=c; } printf("%lld",max(a,b)); return 0; }
标签：最大值 show ace line each include gets pos ide
原文地址：http://www.cnblogs.com/xibeiw/p/7280285.html
