POJ-2828-Buy Tickets (line segment tree)

POJ-2828-Buy Tickets (line segment tree)

 

Topic transfer: Buy Tickets

 

Idea: Line Segment tree, which is inserted in sequence from the back to the back, and inserted with an update

 

AC code:

 

#include 
 
  #include 
  
   #include 
   
    #include #include 
    
     #include 
     
      #include 
      
       #include 
       
        #include
        #include 
         
          #include 
          
           #include 
           
            #define LL long long#define INF 0x7fffffffusing namespace std;const int maxn = 200005;struct node {int pos, v;}a[maxn];int x[maxn << 2], num[maxn];void build(int l, int r, int rt) {x[rt] = r - l + 1;if(r == l) return;int mid = (r + l) >> 1;build(l, mid, rt << 1);build(mid + 1, r, rt << 1 | 1);}int query(int p, int l, int r, int rt) {x[rt] --;if(l == r) return l;int mid = (l + r) >> 1;if(x[rt << 1] >= p) return query(p, l, mid, rt << 1);else return query(p - x[rt << 1], mid + 1, r, rt << 1 | 1);}int main() {int n;while(scanf("%d", &n) != EOF) {for(int i = 1; i <= n; i ++) {scanf("%d %d", &a[i].pos, &a[i].v);}build(1, n, 1);for(int i = n; i >= 1; i --) {int p = query(a[i].pos + 1, 1, n, 1);num[p] = a[i].v;}for(int i = 1; i < n; i ++) {printf("%d ", num[i]);}printf("%d\n", num[n]);}return 0;}