POJ2528 Mayor's posters

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区间线段树水题，离散化怒A= =

我觉得最后算答案哪里应该不用再单独算的= =

好吧，虽然A了，但是我的算法写错了= =

31 101 36 10

这组数据就不对。

应该是把每个数据的+1还有-1也都离散化一下，在做就对了，可是据说这样反而会过不了= =

#include <cstdio>#include <cstring>#include <cstdlib>#include <ctime>#include <climits>#include <cmath>#include <iostream>#include <string>#include <vector>#include <set>#include <map>#include <list>#include <queue>#include <stack>#include <deque>#include <algorithm>using namespace std;typedef long long ll;#define lhs rt<<1#define rhs rt<<1|1const int maxn = 20010;int T, n, l[maxn], r[maxn], ans;int val[maxn*4], lazy[maxn*4];vector<int> num;int tot;map<int, int> dic;bool vis[maxn];void update(int x, int rt, int L, int R){    lazy[rt] = x;    val[rt] = x;}void query(int ql, int qr, int x, int rt = 1, int L = 1, int R = tot){if (ql <= L && R <= qr){    update(x, rt, L, R);    return;}int M = (L+R) >> 1;if (lazy[rt]){    update(lazy[rt], lhs, L, M);    update(lazy[rt], rhs, M+1, R);    lazy[rt] = 0;}if (ql <= M) query(ql, qr, x, lhs, L, M);if (qr > M) query(ql, qr, x, rhs, M+1, R);}void init(int rt = 1, int L = 1, int R = tot){    val[rt] = 0; lazy[rt] = 0;if (L == R) return;int M = (L+R) >> 1;init(lhs, L, M);init(rhs, M+1, R);}void dfs(int rt = 1, int L = 1, int R = tot){    if (L == R){    vis[val[rt]] = 1;    return;}int M = (L+R) >> 1;if (lazy[rt]){    update(lazy[rt], lhs, L, M);    update(lazy[rt], rhs, M+1, R);    lazy[rt] = 0;}dfs(lhs, L, M);dfs(rhs, M+1, R);}int main(){    scanf("%d", &T);    while (T--)    {        scanf("%d", &n);        num.clear();        for (int i=1;i<=n;i++)        {            scanf("%d%d", &l[i], &r[i]);            num.push_back(l[i]);            num.push_back(r[i]);        }        sort(num.begin(), num.end());        num.erase(unique(num.begin(), num.end()), num.end());        tot = num.size();        dic.clear();        for (int i=0;i<tot;i++) dic[num[i]] = i+1;        init();        for (int i=1;i<=n;i++) query(dic[l[i]], dic[r[i]], i);        memset(vis, 0, sizeof(vis));        dfs();        ans = 0;        for (int i=1;i<=n;i++)            if (vis[i]) ans++;        printf("%d\n", ans);    }return 0;}