P4113 [HEOI2012]采花 (莫队TLE)

思路

update 11.2 树状数组ＡＣ
本题莫队过不去，会TLE

但也是个不错的莫队练手题

毕竟Chen_Zhe还给了100分莫队分 （还会给你小对勾）

莫队＆＆树状数组代码

// luogu-judger-enable-o2
#include <cstdio>
#include <algorithm>
using namespace std;
const int maxn = 2e6 + 7;
int n, m, a[maxn], sum[maxn << 1];
struct edge {
    int size,las1,las2;
} zz[maxn];
int ans[maxn];
struct node {
    int s, t,id;
    bool operator < (const node b ) const {
        return t < b.t;
    }
} b[maxn];

int read() {
    int x = 0, f = 1; char s = getchar();
    for (; s < '0' || s > '9'; s = getchar()) if (s == '-') f = -1;
    for (; s >= '0' && s <= '9'; s = getchar()) x = x * 10 + s - '0';
    return x * f;
}

int lowbit(int x) {
    return x & -x;
}

void add(int x, int dat) {
    for (; x <= n; x += lowbit(x))
        sum[x] += dat;
}

int query(int x) {
    int ans = 0;
    for (; x >= 1; x -= lowbit(x))
        ans += sum[x];
    return ans;
}

int main() {
    n = read();
    m = read();
    m=read();
    for (int i = 1; i <= n; ++i)
        a[i] = read();
    for (int i = 1; i <= m; ++i)
        b[i].s = read(), b[i].t = read(), b[i].id = i;
    sort(b + 1, b + 1 + m);
    int js = 1;
    for (int i = 1; i <= n; ++i) {
        if(!zz[a[i]].size) {
            zz[a[i]].las1=i;
        } else {
            if(zz[a[i]].size>=2)
                add(zz[a[i]].las2,-1);
            add(zz[a[i]].las1,1);
            swap(zz[a[i]].las1,zz[a[i]].las2);
            zz[a[i]].las1=i;
        }
        ++zz[a[i]].size;
        if(b[js].t==i) {
            int end_ans=query(b[js].t);
            for(; b[js].t==i; ++js) {
                ans[b[js].id]=end_ans-query(b[js].s-1);
            }
        }
    }
    for (int i = 1; i <= m; ++i) {
        printf("%d
", ans[i]);
    }
    return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#define maxn 	2000007
using namespace std;
inline int read()
{
    int x=0,f=1;char s=getchar();
    while('0'>s||s>'9') {
        if(s=='-') f=-1;
        s=getchar();
    }
    while('0'<=s&&s<='9') {
        x=x*10+s-'0';
        s=getchar();
    }
    return x*f;
}
int n,m,k,now;
int a[maxn];
int belong[maxn];
int vis[maxn];
int ans[maxn]; 
struct node{
	int l,r,id;
}q[maxn];
inline bool cmp(const node &a,const node &b)
{
	return belong[a.l]==belong[b.l] ? a.r<b.r :  belong[a.l]<belong[b.l];
}
inline void Add(int x)
{
	vis[x]==1 ? ++now : now;
	++vis[x];
}
inline void Delet(int x)
{
	vis[x]==2 ? --now : now;
	--vis[x];
}
int main()
{
	n=read();
	int meiyongdebianliang_qidaotixingfanweidezuoye__233zhemechangdebianliangming=read();
	m=read();	
	k=sqrt(n);
	for(int i=1;i<=n;++i)
		a[i]=read();
	for(int i=1;i<=n;++i)
		belong[i]=(i-1)/k+1;
	for(int i=1;i<=m;++i)
	{
		q[i].l=read();
		q[i].r=read();
		q[i].id=i;	
	}
	sort(q+1,q+1+m,cmp);
	int l=1,r=0;
	for(int i=1;i<=m;++i)
	{
		while(l > q[i].l) Add(a[--l]);
		while(l < q[i].l) Delet(a[l++]);
		while(r < q[i].r) Add(a[++r]);
		while(r > q[i].r) Delet(a[r--]);
		ans[q[i].id]=now; 
	}
	for(int i=1;i<=m;++i) 
		printf("%d
",ans[i]); 
	return 0;
}