链接：
http://poj.org/problem?id=3667
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 = 5e4 + 7; 29 // head 30 31 int cover[MAXN << 2]; 32 int lsum[MAXN << 2], rsum[MAXN << 2], msum[MAXN << 2]; 33 34 void pushup(int rt, int m) { 35 lsum[rt] = lsum[rt << 1], rsum[rt] = rsum[rt << 1 | 1]; 36 if (lsum[rt << 1] == m - (m >> 1)) lsum[rt] += lsum[rt << 1 | 1]; 37 if (rsum[rt << 1 | 1] == m >> 1) rsum[rt] += rsum[rt << 1]; 38 msum[rt] = max(max(msum[rt << 1], msum[rt << 1 | 1]), rsum[rt << 1] + lsum[rt << 1 | 1]); 39 } 40 41 void pushdown(int rt, int m) { 42 if (cover[rt] != -1) { 43 cover[rt << 1] = cover[rt << 1 | 1] = cover[rt]; 44 lsum[rt << 1] = rsum[rt << 1] = msum[rt << 1] = (cover[rt] ? 0 : m - (m >> 1)); 45 lsum[rt << 1 | 1] = rsum[rt << 1 | 1] = msum[rt << 1 | 1] = (cover[rt] ? 0 : m >> 1); 46 cover[rt] = -1; 47 } 48 } 49 50 void build(int l, int r, int rt) { 51 cover[rt] = -1; 52 lsum[rt] = rsum[rt] = msum[rt] = r - l + 1; 53 if (l == r) return; 54 int m = (l + r) >> 1; 55 build(lson); 56 build(rson); 57 } 58 59 void update(int L, int R, int x, int l, int r, int rt) { 60 if (L <= l && r <= R) { 61 cover[rt] = x; 62 lsum[rt] = rsum[rt] = msum[rt] = (x ? 0 : r - l + 1); 63 return; 64 } 65 pushdown(rt, r - l + 1); 66 int m = (l + r) >> 1; 67 if (L <= m) update(L, R, x, lson); 68 if (R > m) update(L, R, x, rson); 69 pushup(rt, r - l + 1); 70 } 71 72 int query(int x, int l, int r, int rt) { 73 if (l == r) return l; 74 pushdown(rt, r - l + 1); 75 int m = (l + r) >> 1; 76 if (msum[rt << 1] >= x) return query(x, lson); 77 else if (rsum[rt << 1] + lsum[rt << 1 | 1] >= x) return m - rsum[rt << 1] + 1; 78 else query(x, rson); 79 } 80 81 int main() { 82 int n, m; 83 cin >> n >> m; 84 build(1, n, 1); 85 while (m--) { 86 int a, b, c; 87 scanf("%d", &a); 88 if (a == 1) { 89 scanf("%d", &b); 90 if (msum[1] < b) { 91 puts("0"); 92 continue; 93 } 94 int ans = query(b, 1, n, 1); 95 printf("%d ", ans); 96 update(ans, ans + b - 1, 1, 1, n, 1); 97 } 98 else { 99 scanf("%d%d",&b, &c); 100 update(b, b + c - 1, 0, 1, n, 1); 101 } 102 } 103 return 0; 104 }