HDU 3015 Disharmony Trees（树状数组）

#include<set>
#include<map>
#include<queue>
#include<stack>
#include<cmath>
#include<vector>
#include<string>
#include<cstdio>
#include<cstring>
#include<stdlib.h>
#include<iostream>
#include<algorithm>
using namespace std;
#define eps 1E-8
/*注意可能会有输出-0.000*/
#define Sgn(x) (x<-eps? -1 :x<eps? 0:1)//x为两个浮点数差的比较,注意返回整型
#define Cvs(x) (x > 0.0 ? x+eps : x-eps)//浮点数转化
#define zero(x) (((x)>0?(x):-(x))<eps)//判断是否等于0
#define mul(a,b) (a<<b)
#define dir(a,b) (a>>b)
typedef long long ll;
typedef unsigned long long ull;
const int Inf=1<<28;
const double Pi=acos(-1.0);
const int Mod=1e9+7;
const int Max=100010;
struct node
{
    int sub,minx;
} tree[Max];
int n;
bool cmpt(struct node p1,struct node p2)
{
    return p1.sub<p2.sub;
}
bool cmp(struct node p1,struct node p2)
{
    return p1.minx<p2.minx;//按照最值排序才能固定一个值
}
int lowbit(int x)
{
    return x&(-x);
}
void Add(ll *bit,int x,ll y)
{
    while(x<=n)
    {
        bit[x]+=y;
        x+=lowbit(x);
    }
    return;
}
ll Sum(ll *bit,int x)
{
    ll sum=0ll;
    while(x)
    {
        sum+=bit[x];
        x-=lowbit(x);
    }
    return sum;
}
ll bit[Max],bit2[Max];//存个数 存大小
ll Solve()
{
    ll ans=0ll;
    memset(bit,0ll,sizeof(bit));
    memset(bit2,0ll,sizeof(bit2));
    for(int i=0;i<n;++i)
    {
        Add(bit2,tree[i].sub,(ll)tree[i].sub);
        Add(bit,tree[i].sub,1ll);
    }
    for(int i=0;i<n;++i)
    {
        Add(bit2,tree[i].sub,(ll)-tree[i].sub);
        Add(bit,tree[i].sub,-1ll);
       // printf("%d\n",tree[i].sub);
        ans+=(ll)tree[i].minx*(
        Sum(bit2,n)-Sum(bit2,tree[i].sub)-(ll)tree[i].sub*(Sum(bit,n)-Sum(bit,tree[i].sub))+
        (ll)tree[i].sub*Sum(bit,tree[i].sub)-Sum(bit2,tree[i].sub));//关键
        //printf("%I64d %I64d\n",ans,Sum(bit2,n)-Sum(bit,n)*tree[i].sub);
    }
    return ans;
}
int main()
{
    int tmp;
    while(~scanf("%d",&n))
    {
        for(int i=0; i<n; ++i)
            scanf("%d %d",&tree[i].sub,&tree[i].minx);
        sort(tree,tree+n,cmpt);//离散化
        tree[n].sub=tree[n].minx=-1;
        tmp=1;
        for(int i=0; i<n; ++i)
        {
            if(tree[i].sub!=tree[i+1].sub)
            {
                tree[i].sub=tmp;
                tmp=i+2;
            }
            else
            {
                tree[i].sub=tmp;
            }
        }
        sort(tree,tree+n,cmp);
        tmp=1;
                for(int i=0; i<n; ++i)
        {
            if(tree[i].minx!=tree[i+1].minx)
            {
                tree[i].minx=tmp;
                tmp=i+2;
            }
            else
            {
                tree[i].minx=tmp;
            }
        }
      //  for(int i=0;i<n;++i)
        //    printf("%d %d\n",tree[i].sub,tree[i].minx);
        printf("%I64d\n",Solve());
    }
    return 0;
}