poj2828 Buy Tickets

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 #define lson (u << 1)
 5 #define rson (u << 1 | 1)
 6 #define max(a, b) (a > b ? a : b)
 7 #define min(a, b) (a < b ? a : b)
 8 //using namespace std;
 9 const int maxn = 2e5 + 10;
10 
11 struct Seg{
12     int l, r, maxi, mini;
13     int lazy;
14 }seg[maxn << 2];
15 int n;
16 int b[maxn], c[maxn];
17 
18 void push_up(int u){
19     seg[u].maxi = max(seg[lson].maxi, seg[rson].maxi);
20     seg[u].mini = min(seg[lson].mini, seg[rson].mini);
21 }
22 
23 void build(int u, int l, int r){
24     seg[u].l = l, seg[u].r = r, seg[u].lazy = 0;
25     if(r - l < 2){
26         seg[u].maxi = seg[u].mini = l;
27         return;
28     }
29     int mid = (l + r) >> 1;
30     build(lson, l, mid);
31     build(rson, mid, r);
32     push_up(u);
33 }
34 
35 int ans[maxn];
36 
37 void push_down(int u){
38     if(seg[u].r - seg[u].l > 1 && seg[u].lazy != 0){
39         seg[lson].maxi -= seg[u].lazy, seg[rson].maxi -= seg[u].lazy;
40         seg[lson].mini -= seg[u].lazy, seg[rson].mini -= seg[u].lazy;
41         seg[lson].lazy += seg[u].lazy, seg[rson].lazy += seg[u].lazy;
42         seg[u].lazy = 0;
43     }
44 }
45 
46 void update(int u, int l, int r, int L, int R){
47     if(L == l && r == R){
48         seg[u].maxi--, seg[u].mini--;
49         seg[u].lazy++;
50         return;
51     }
52     push_down(u);
53     int mid = (l + r) >> 1;
54     if(R <= mid) update(lson, l, mid, L, R);
55     else if(L >= mid) update(rson, mid, r, L, R);
56     else{
57         update(lson, l, mid, L, mid);
58         update(rson, mid, r, mid, R);
59     }
60     push_up(u);
61 }
62 
63 int query(int u, int l, int r, int v){
64     if(r - l < 2) return l;
65     push_down(u);
66     int mid = (l + r) >> 1;
67     if(v >= seg[lson].mini && seg[lson].maxi >= v) return query(lson, l, mid, v);
68     return query(rson, mid, r, v);
69 }
70 
71 int main(){
72     freopen("in.txt", "r", stdin);
73     while(~scanf("%d", &n)){
74         for(int i = 1; i <= n; i++){
75             scanf("%d%d", &b[i], &c[i]);
76         }
77         build(1, 1, n + 1);
78         for(int i = n; i >= 1; i--){
79             //find the position to insert
80             int pos = query(1, 1, n + 1, b[i] + 1);
81             ans[pos] = c[i];
82             update(1, 1, n + 1, pos, n + 1);
83         }
84         printf("%d", ans[1]);
85         for(int i = 2; i <= n; i++) printf(" %d", ans[i]);
86         putchar(‘\n‘);
87     }
88     return 0;
89 }