●洛谷P1903 [国家集训队]数颜色

题链:

https://www.luogu.org/problemnew/show/P1903
题解:

序列带修莫队,

推荐博客https://www.cnblogs.com/Paul-Guderian/p/6933799.html

复杂度$O(N^{\frac{5}{3}})$
代码:

include<bits/stdc++.h>
#define MAXN 10005
using namespace std;
int N,M,BLOCK,ans;
int color[1000006],s[MAXN],bel[MAXN],ANS[MAXN];
struct Query{
	int l,r,t,id;
	bool operator < (const Query &rtm) const{
		return bel[l]==bel[rtm.l]?(bel[r]==bel[rtm.r]?t<rtm.r:bel[r]<bel[rtm.r]):bel[l]<bel[rtm.l];
	}
}Q[MAXN];
struct Change{int p,newval,oldval;}C[MAXN];
int L=1,R,T;
void modify(int p,int k){
	color[s[p]]+=k;
	if(color[s[p]]==0&&k==-1) ans--;
	if(color[s[p]]==1&&k==1) ans++;
}
void dotime(int p,int v){
	if(L<=p&&p<=R) modify(p,-1),s[p]=v,modify(p,1);
	else s[p]=v;
}
int main(){
	static int now[MAXN];
	char ch; int x,y,qnt=0,tim=0;
	scanf("%d%d",&N,&M); BLOCK=pow(N,2.0/3);
	for(int i=1;i<=N;i++) bel[i]=i/BLOCK;
	for(int i=1;i<=N;i++) scanf("%d",&s[i]),now[i]=s[i];
	for(int i=1;i<=M;i++){
		scanf(" %c%d%d",&ch,&x,&y);
		if(ch=='Q') qnt++,Q[qnt]=(Query){x,y,tim,qnt};
		else tim++,C[tim]=(Change){x,y,now[x]},now[x]=y;
	}
	sort(Q+1,Q+qnt+1);
	for(int i=1;i<=qnt;i++){
		while(T<Q[i].t) T++,dotime(C[T].p,C[T].newval);
		while(T>Q[i].t) dotime(C[T].p,C[T].oldval),T--;
		while(R<Q[i].r) R++,modify(R,1);
		while(R>Q[i].r) modify(R,-1),R--;
		while(L<Q[i].l) modify(L,-1),L++;
		while(L>Q[i].l) L--,modify(L,1);
		ANS[Q[i].id]=ans;
	}
	for(int i=1;i<=qnt;i++) printf("%d\n",ANS[i]);
	return 0;
}

  

 

posted @ 2018-03-12 21:19  *ZJ  阅读(151)  评论(0编辑  收藏  举报