HDOJ 1556 线段树
链接：
http://acm.hdu.edu.cn/showproblem.php?pid=1556
题解：
之前偷懒使用前缀和写的，最近要复习一下线段树，所以又用线段树写了一下
另外是时候修改一下自己的//head了
代码：
1 #include <map> 2 #include <set> 3 #include <cmath> 4 #include <queue> 5 #include <stack> 6 #include <cstdio> 7 #include <string> 8 #include <vector> 9 #include <cstdlib> 10 #include <cstring> 11 #include <sstream> 12 #include <iostream> 13 #include <algorithm> 14 #include <functional> 15 using namespace std; 16 #define rep(i,a,n) for (int i=a;i<n;i++) 17 #define per(i,a,n) for (int i=n-1;i>=a;i--) 18 #define all(x) (x).begin(),(x).end() 19 #define pb push_back 20 #define mp make_pair 21 #define lson l,m,rt<<1 22 #define rson m+1,r,rt<<1|1 23 typedef long long ll; 24 typedef vector<int> VI; 25 typedef pair<int, int> PII; 26 const ll MOD = 1e9 + 7; 27 const int INF = 0x3f3f3f3f; 28 const int MAXN = 2e5 + 7; 29 // head 30 31 int n; 32 int tree[MAXN << 2], lazy[MAXN << 2]; 33 34 void pushdown(int rt) { 35 if (lazy[rt] != 0) { 36 tree[rt << 1] += lazy[rt]; 37 tree[rt << 1 | 1] += lazy[rt]; 38 lazy[rt << 1] += lazy[rt]; 39 lazy[rt << 1 | 1] += lazy[rt]; 40 lazy[rt] = 0; 41 } 42 } 43 44 void update(int L, int R, int l, int r, int rt) { 45 if (L <= l && r <= R) { 46 tree[rt]++; 47 lazy[rt]++; 48 return; 49 } 50 pushdown(rt); 51 int m = (l + r) >> 1; 52 if (L <= m) update(L, R, lson); 53 if (R > m) update(L, R, rson); 54 } 55 56 int query(int k, int l, int r, int rt) { 57 if (l == r) return tree[rt]; 58 pushdown(rt); 59 int m = (l + r) >> 1; 60 if (k <= m) query(k, lson); 61 else query(k, rson); 62 } 63 64 int main() { 65 while (cin >> n, n) { 66 memset(tree, 0, sizeof(tree)); 67 memset(lazy, 0, sizeof(lazy)); 68 rep(i, 0, n) { 69 int a, b; 70 scanf("%d%d", &a, &b); 71 update(a, b, 1, n, 1); 72 } 73 cout << query(1, 1, n, 1); 74 rep(i, 2, n + 1) printf(" %d", query(i, 1, n, 1)); 75 cout << endl; 76 } 77 return 0; 78 }
