Poj2528Mayor's posters线段树

　　离散化搞下。就是8 9 19  分别映射到 1 2 3 上。用map好像会超时，可能自己写戳了。

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <climits>

#include <string>

#include <iostream>

#include <map>

#include <cstdlib>

#include <list>

#include <set>

#include <queue>

#include <stack>

#include<math.h>

using namespace std;

#define lson l,mid,rt<<1

#define rson mid+1,r,rt<<1|1

const int maxn = 44444;

int color[maxn << 2];

int vis[maxn];

int q[maxn];

int q1[maxn];

int l[maxn];

int r[maxn];

int Hash[maxn];

void down(int rt)

{

    if (color[rt]){

        color[rt << 1] = color[rt << 1 | 1] = color[rt];

        color[rt] = 0;

    }

}



void build(int l, int r, int rt)

{

    color[rt] = 0;

    if (l == r) return;

    int mid = (l + r) >> 1;

    build(lson);

    build(rson);

}



void update(int L, int R, int add, int l, int r, int rt)

{

    if (L <= l&&r <= R){

        color[rt] = add; return;

    }

    down(rt);

    int mid = (l + r) >> 1;

    if (L <= mid) update(L, R, add, lson);

    if (R>mid) update(L, R, add, rson);

}



void ask(int l, int r, int rt)

{

    if (color[rt]){

        Hash[color[rt]] = 1; return;

    }

    int mid = (l + r) >> 1;

    ask(lson); ask(rson);

}



int erfen(int key, int a[], int len)

{

    int l = 0; int r = len - 1;

    while (l <= r){

        int mid = (l + r) >> 1;

        if (a[mid] == key) return mid + 1;

        if (a[mid]<key) l = mid + 1;

        if (a[mid]>key) r = mid - 1;

    }

}

int cmp(const int &a, const int &b)

{

    return a<b;

}

int main()

{

    int Icase, n;

    int ans, ans1;

    scanf("%d", &Icase);

    while (Icase--){

        ans = 0; ans1 = 0;

        memset(Hash, 0, sizeof(Hash));

        scanf("%d", &n);

        for (int i = 0; i<n; i++){

            scanf("%d%d", &l[i], &r[i]);

            q[ans++] = l[i]; q[ans++] = r[i];

        }

        sort(q, q + ans, cmp);

        memset(vis, 0, sizeof(vis));

        for (int i = 0; i<ans - 1; i++){

            if (q[i] == q[i + 1]) vis[i + 1] = 1;

        }

        int ans1 = 0;

        for (int i = 0; i<ans; i++)

        if (!vis[i]) q1[ans1++] = q[i];

        for (int i = 0; i<n; i++){

            l[i] = erfen(l[i], q1, ans1); r[i] = erfen(r[i], q1, ans1);

        }

        build(1, ans1, 1);

        for (int i = 0; i<n; i++){

            update(l[i], r[i], i + 1, 1, ans1, 1);

        }

        ask(1, ans1, 1);

        int gg = 0;

        for (int i = 1; i <= n; i++)

        if (Hash[i]) gg++;

        cout << gg << endl;

    }

    return 0;

}