【POJ】2528 Mayor's posters

离散化+线段树。
数组开的不够大，wa了N多回。

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;

 #define MAXN 12010
 #define lson l, mid, rt<<1
 #define rson mid+1, r, rt<<1|1

 int ls[MAXN], rs[MAXN];
 int nums[MAXN<<];
 int buf[MAXN*], cnt;
 char set[MAXN];

 inline int bin(int x, int n) {
     int l = , r = n-;
     int mid;

     while (l <= r) {
         mid = (l+r)>>;
         if (buf[mid] == x)
             return mid;
         if (buf[mid] < x)
             l = mid+;
         else
             r = mid-;
     }

     return -;
 }
 /*
 void build(int l, int r, int rt) {
     nums[rt] = 0;
     if (l == r)
         return ;
     int mid = (l+r)>>1;
     build(lson);
     build(rson);
 }*/

 inline void PushDown(int rt) {
     if ( nums[rt] ) {
         nums[rt<<] = nums[rt<<|] = nums[rt];
         nums[rt] = ;
     }
 }

 void update(int ll, int rr, int c, int l, int r, int rt) {
     if (ll<=l && rr>=r) {
         nums[rt] = c;
         return ;
     }
     PushDown(rt);
     int mid = (l+r)>>;
     if (ll <= mid)
         update(ll, rr, c, lson);
     if (rr > mid)
         update(ll, rr, c, rson);
 }

 void query(int l, int r, int rt) {
     if ( nums[rt] ) {
         if ( !set[nums[rt]] )
             ++cnt;
         set[nums[rt]] = ;
         return ;
     }
     if (l == r)
         return ;
     int mid = (l+r)>>;
     query(lson);
     query(rson);
 }

 int main() {
     int case_n, n, m;
     int i, j, ll, rr;

     scanf("%d", &case_n);

     while (case_n--) {
         scanf("%d", &n);
         m = ;
         for (i=; i<=n; ++i) {
             scanf("%d %d", &ls[i], &rs[i]);
             buf[m++] = ls[i];
             buf[m++] = rs[i];
         }
         sort(buf, buf+m);
         j = ;
         for (i=; i<m; ++i) {
             if (buf[i] != buf[i-])
                 buf[j++] = buf[i];
         }
         m = j;
         for (i=m-; i>; --i) {
             if (buf[i] != buf[i-]+)
                 buf[m++] = buf[i-]+;
         }
         sort(buf, buf+m);
         //build(0, m, 1);
         memset(nums, , sizeof(nums));
         memset(set, , sizeof(set));
         for (i=; i<=n; ++i) {
             ll = bin(ls[i], m);
             rr = bin(rs[i], m);
             update(ll, rr, i, , m, );
         }
         cnt = ;
         query(, m, );
         printf("%d\n", cnt);
     }

     return ;
 }