【HDOJ】4325 Flowers

树状数组+离散化的题目，一直在思考为什么结果不一样，后来才发现花开了就是开了不会再谢了。

 /* 4325 */
 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
 #include <algorithm>
 using namespace std;

 #define MAXN 100005

 typedef struct {
     int s, t;
 } node_t;

 node_t nodes[MAXN];
 int qi[MAXN];
 int buf[MAXN*];
 int sum[MAXN];

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

 void update(int i, int v, int n) {
     while (i <= n) {
         sum[i] += v;
         i += lowbit(i);
     }
 }

 int query(int i) {
     int ret = ;

     while (i) {
         ret += sum[i];
         i -= lowbit(i);
     }

     return ret;
 }

 int main() {
     int t, n, m, l;
     int i, j, k, tmp;
     int a, b, c;

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
     #endif

     scanf("%d", &t);
     for (int tt=; tt<=t; ++tt) {
         scanf("%d %d", &n, &m);
         l = ;
         for (i=; i<n; ++i) {
             scanf("%d %d", &nodes[i].s, &nodes[i].t);
             buf[l++] = nodes[i].s;
             buf[l++] = nodes[i].t;
         }
         for (i=; i<m; ++i) {
             scanf("%d", &qi[i]);
             buf[l++] = qi[i];
         }

         // discretization
         buf[l++] = ;
         sort(buf, buf+l);
         c = unique(buf, buf+l) - buf;

         memset(sum, , sizeof(sum));
         for (i=; i<n; ++i) {
             a = lower_bound(buf, buf+c, nodes[i].s) - buf + ;
             b = lower_bound(buf, buf+c, nodes[i].t) - buf + ;
             update(a, , c);
             update(b+, -, c);
         }

         printf("Case #%d:\n", tt);
         for (i=; i<m; ++i) {
             j = lower_bound(buf, buf+c, qi[i]) - buf + ;
             k = query(j);
             printf("%d\n", k);
         }
     }

     return ;
 }