1664 - Movie Festival Queries.cpp

/*
Problem Name: Movie Festival Queries
Problem Link: https://cses.fi/problemset/task/1664
Author: Sachin Srivastava (mrsac7)
*/
#include<bits/stdc++.h>
using namespace std;

#define int long long
#define endl '\n'

int dp[1000006][25];
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    #ifdef LOCAL
    freopen("input.txt", "r" , stdin);
    freopen("output.txt", "w", stdout);
    #endif
    
    int n, m; cin>>n>>m;
    for (int i = 0; i < n; i++) {
        int x, y; cin>>x>>y;
        dp[y][0] = max(dp[y][0], x);
    }
    for (int i = 1; i <= 1000000; i++) 
        dp[i][0] = max(dp[i][0], dp[i-1][0]);
    
    for (int k = 1; k <= 20; k++) 
        for (int i = 1; i <= 1000000; i++) 
            dp[i][k] = dp[dp[i][k-1]][k-1];

    while(m--) {
        int x,y; cin>>x>>y;
        int ans = 0;
        while(y>0) {
            int z = 0;
            for (int i = 0; i <= 20; i++) {
                if (dp[y][i] < x) {
                    z = i;
                    break;
                }
            }
            
            if (z == 0)
                break;
            ans += (1<<(z-1));
            y = dp[y][z-1];
        }
        cout<<ans<<endl;
    }
   
}