C. Little Girl and Maximum Sum Codeforces Round #169 (Div. 2)

http://codeforces.com/contest/276/problem/C  原题连接

解题说明：题目的意思是有若干对区间和的查询，问如何重组数组使查询结果的和最大。

我的解法就是将对应的频率排序之后在求(求频率那里需要点思维嘻嘻

直接贴代码了

#include <algorithm>
#include <stack>
#include <istream>
#include <stdio.h>
#include <map>
#include <math.h>
#include <vector>
#include <iostream>
#include <queue>
#include <string.h>
#include <set>
#include <cstdio>
#define FR(i,n) for(int i=0;i<n;i++)
#define MAX 2005
#define mkp pair <int,int>
using namespace std;
const int maxn = 4e5 + 40;
typedef long long ll;
const int  inf = 0x3fffff;
void read(ll &x) {
    char ch; bool flag = 0;
    for (ch = getchar(); !isdigit(ch) && ((flag |= (ch == '-')) || 1); ch = getchar());
    for (x = 0; isdigit(ch); x = (x << 1) + (x << 3) + ch - 48, ch = getchar());
    x *= 1 - 2 * flag;
}

ll val[maxn];
int vis[maxn];

struct inof{
   ll  l;
   bool flag;
}fuck[maxn];

bool cmp(inof a,inof b)
{
    return a.l<b.l;
}
int res[maxn];
int main() {
    ll n,m;
    memset(vis,0,sizeof(vis));
    read(n),read(m);
    for(int i=1;i<=n;i++){
        read(val[i]);
    }
    int top = 0;
    while(m--){
       // ll l,r;
        read(fuck[top].l);
        fuck[top].flag=1;
        top++;
        read(fuck[top].l);
        fuck[top].l++;
        fuck[top].flag=0;
        top++;
        //read(l),read(r);
        //vis[l]++,vis[r+1]--;
    }
    sort(fuck,fuck+top,cmp);
    int sub = 0;
    int maxx = 0;
    for(int i=0;i<top;i++)
    {
        if(i)vis[sub]+=fuck[i].l-fuck[i-1].l;
        if(fuck[i].flag)sub++;
        else sub--;
        maxx=max(maxx,sub);
    }
    ll ans = 0;
    sort(val+1,val+n+1);
  //  sort(vis,vis+maxx+1);
    int temp = n;
    for(int i=maxx;i>=0;i--)
    {
        if(vis[i])
        {
            while(temp>=1&&vis[i])vis[i]--,ans+=val[temp]*i,temp--;
        }
        if(temp==0)break;
    }
    cout<<ans<<endl;
    return 0;
}