HDU 4288

线段树

每个区间记录该区间内sum[0...4],在区间合并用时注意右区间需要用上左区间的所含元素个数。

#include<cstdio>#include<algorithm>#include<cstring>#define N 100100typedef long long ll;using namespace std;struct Point{    int l,r;    int num;//number in the interval    ll sum[5];//sum of the asked number in the interval}tree[N*3];int sel[N],pn[N],px[N];void build(int s,int t,int id){    tree[id].l=s,tree[id].r=t,tree[id].num=0;    for(int i=0;i<5;i++)tree[id].sum[i]=0;    if(s!=t){        int mid=(s+t)>>1;        build(s,mid,id<<1);        build(mid+1,t,id<<1|1);    }}void insert(int pos,int number,int inc,int id){    int i;    if(tree[id].l==tree[id].r){        tree[id].num+=inc;        tree[id].sum[1]+=number;        return ;    }    int mid=(tree[id].l+tree[id].r)>>1;    if(pos<=mid)insert(pos,number,inc,id<<1);    else if(pos>mid)insert(pos,number,inc,id<<1|1);    tree[id].num=tree[id<<1].num+tree[id<<1|1].num;    for(i=0;i<5;i++)        tree[id].sum[i]=tree[id<<1].sum[i]+tree[id<<1|1].sum[(i-tree[id<<1].num+1000000)%5];}int main(){    char s[10];    int i,k,tem,pos,n;    while(scanf("%d",&n)!=EOF){        k=0;        for(i=1;i<=n;i++){            scanf("%s",s);            if(s[0]=='a'){                sel[i]=1;                scanf("%d",&tem);                pn[i]=px[k++]=tem;            }            else if(s[0]=='d'){                sel[i]=2;                scanf("%d",&tem);                pn[i]=tem;            }            else                sel[i]=3;        }        sort(px,px+k);        int nn=unique(px,px+k)-px;        if(nn!=0)            build(1,nn,1);        for(i=1;i<=n;i++){            if(sel[i]==1){                pos=lower_bound(px,px+nn,pn[i])-px+1;                insert(pos,pn[i],1,1);            }            else if(sel[i]==2){                pos=lower_bound(px,px+nn,pn[i])-px+1;                insert(pos,-pn[i],-1,1);            }            else{                if(nn==0)                    printf("0\n");                else                    printf("%I64d\n",tree[1].sum[3]);            }        }    }}