hdu 2852 KiKi’s K-Number（樹狀數組+二分）

3個操作:

0：插入

1: 刪除，如果沒有，則輸出  No Elment!

2:尋找比a大k個數的數

本來想用堆做，結果優先隊列沒有彈出任意一個數的操作。只能放棄，看大神都是二分做的。

/*Problem ID:meaning:Analyzing:*/#include <iostream>#include <algorithm>#include<cstdio>#include<cmath>#include<cstdlib>#include<cstring>#include<vector>#include<queue>using namespace std;typedef struct even{int y1,y2,x;}even;#define clr(A,k) memset(A,k,sizeof(A))#define FOR(i,s,t) for(int i=(s); i<(t); i++)#define LL long long#define BUG puts("here!!!")#define print(x) printf("%d\n",x)#define STOP system("pause")#define eps 1e-8#define PI acos(-1.0)#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1#define maxn 100001#define lowbit(x) x&(-x)LL gcd(LL a,LL b) {return a?gcd(b%a,a):b;}priority_queue<int>q1;int A[maxn],C[maxn];void update(int pos,int val){    while(pos<maxn){        C[pos]+=val;        pos+=lowbit(pos);    }}int query(int x){    int ret=0;    while(x>0){        ret+=C[x];        x-=lowbit(x);    }    return ret;}int binsearch(int a,int k){    int l=a+1;    int r=maxn-1;    int ans=maxn;    int s1=query(a);    while(l<=r){        int m=(l+r)>>1;        int s2=query(m);        if(s2-s1>=k){            r=m-1;            if(m<ans) ans=m;        }        else {            l=m+1;        }    }    return ans;}int main(){    int m,op,a,k,e;    while(~scanf("%d",&m)){        clr(A,0);        clr(C,0);        int len=0;        while(m--){            scanf("%d",&op);            if(op==0){                scanf("%d",&e);                if(A[e]==0) update(e,1);            }            else if(op==1) {                scanf("%d",&e);                if(query(e)-query(e-1)==0) puts("No Elment!");                else                    update(e,-1);            }            else if(op==2){                scanf("%d%d",&a,&k);                int ret=binsearch(a,k);                if(ret==maxn) puts("Not Find!");                else printf("%d\n",ret);            }        }    }return 0;}