hdu 2852 KiKi's K-Number

树状数组+二分查找

/* ***********************************************Author        :xryzEmail         :[e-mail] Time  :4-26 22:23:18File Name     :KiKi's K-Number.cpp************************************************ */#include <stdio.h>#include <string.h>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <set>#include <map>#include <string>#include <math.h>#include <stdlib.h>#include <time.h>using namespace std;const int N=100000+5;int p[N];int lowbit(int x){    return x&-x;}int sum(int x){    int ret=0;    while(x>0)    {        ret+=p[x];        x-=lowbit(x);    }    return ret;}void add(int x,int d){    while(x<=N)    {        p[x]+=d;        x+=lowbit(x);    }}int binaryfind(int a,int k){    int low=a+1,high=N-1,mid;    int t=sum(a);    int ans=N,num;    while(high>=low)    {        mid=(low+high)>>1;        num=sum(mid);        if(num-t>=k)        {            high=mid-1;            if(mid<ans)                ans=mid;        }        else low=mid+1;    }    return ans;}int main(){    int k,m,t,a;    while(~scanf("%d",&k))    {        memset(p,0,sizeof(p));        while(k--)        {            scanf("%d",&m);            if(m==0)            {                scanf("%d",&t);                add(t,1);            }            else if(m==1)            {                scanf("%d",&t);                if(sum(t)-sum(t-1)>=1)                {                    add(t,-1);                }                else                    printf("No Elment!\n");            }            else if(m==2)            {                scanf("%d%d",&a,&t);                int f=binaryfind(a,t);                if(f==N)                    printf("Not Find!\n");                else printf("%d\n",f);            }        }    }    return 0;}