Revise paste Untitled

#include <iostream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <fstream>
#include <map>
#include <stack>
using namespace std;
typedef long long ll;
const int INF = 1e9;
const int maxn = 21;
int n, x;
int a[maxn];
pair<int, int> dp[1 << maxn];

int main()
{
    ios_base::sync_with_stdio(false);
//    ifstream cin("in.txt");
    cin >> n >> x;
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }
    dp[0] = make_pair(1, 0);
    for(int mask = 1; mask < (1 << n); mask++) {
        dp[mask] = make_pair(n + 1, 0);
        for(int i = 0; i < n; i++) {
            if(mask & (1 << i)) {
            pair<int, int> tmp = dp[mask ^ (1 << i)];
            if(tmp.second + a[i] <= x) {
                tmp.second += a[i];
            }
            else {
                tmp.first += 1;
                tmp.second = a[i];
            }
            dp[mask] = min(dp[mask], tmp);
            }
            
        }
    }
    cout << dp[(1<<n) - 1].first << endl;
    
        return 0;
}
/*

4 10
 4 8 6 1

4 + 6
 8 + 1

f(taken) --> f(taken2)
 
 f(0000) --> f(1000) + 0
 f(1000) --> f(1010) + 1
 
 dp[taken][2]
 dp[taken][0] --> minimum weight sum of people till the previous move
 dp[taken][1] --> minimum number of elevator rides
 
 8 6 4 1
 
 dp[taken] --> minimum number of elevator calls till this mask
 
 // 2 ^ 20 -->
   27 40 16 50
 
 f(taken, left) --> f(taken2, left + a[j])
 
 f(1111)
 
 pair<int, int> dp[1 << n];
 dp[0] = make_pair(0, x)