Score : 200 points
Problem Statement
Snuke is having a barbeque party.
At the party, he will make N servings of Skewer Meal.
Example of a serving of Skewer Meal
He has a stock of 2N skewers, all of which will be used in Skewer Meal. The length of the i-th skewer is Li. Also, he has an infinite supply of ingredients.
To make a serving of Skewer Meal, he picks 2 skewers and threads ingredients onto those skewers. Let the length of the shorter skewer be x, then the serving can hold the maximum of x ingredients.
What is the maximum total number of ingredients that his N servings of Skewer Meal can hold, if he uses the skewers optimally?
Constraints
- 1≦N≦100
- 1≦Li≦100
- For each i, Li is an integer.
Input
The input is given from Standard Input in the following format:
N L1 L2 … L2N
Output
Print the maximum total number of ingredients that Snuke‘s N servings of Skewer Meal can hold.
Sample Input 1
2 1 3 1 2
Sample Output 1
3
If he makes a serving using the first and third skewers, and another using the second and fourth skewers, each serving will hold 1 and 2 ingredients, for the total of3.
Sample Input 2
5 100 1 2 3 14 15 58 58 58 29
Sample Output 2
135
挺有意思的题目，排个序就ok了
/* ***********************************************
Author :guanjun
Created Time :2016/7/16 23:23:01
File Name :agc1a.cpp
************************************************ */
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <stdio.h>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <iomanip>
#include <list>
#include <deque>
#include <stack>
#define ull unsigned long long
#define ll long long
#define mod 90001
#define INF 0x3f3f3f3f
#define maxn 10010
#define cle(a) memset(a,0,sizeof(a))
const ull inf = 1LL << 61;
const double eps=1e-5;
using namespace std;
priority_queue<int,vector<int>,greater<int> >pq;
struct Node{
int x,y;
};
struct cmp{
bool operator()(Node a,Node b){
if(a.x==b.x) return a.y> b.y;
return a.x>b.x;
}
};
bool cmp(int a,int b){
return a>b;
}
int a[300];
int main()
{
#ifndef ONLINE_JUDGE
//freopen("in.txt","r",stdin);
#endif
//freopen("out.txt","w",stdout);
int n;
while(cin>>n){
for(int i=1;i<=n*2;i++)cin>>a[i];
sort(a+1,a+1+2*n);
int sum=0;
for(int i=2*n;i>=1;i-=2){
sum+=a[i-1];
}
cout<<sum<<endl;
}
return 0;
}