Submission #1245153

#	Time	Username	Problem	Language	Result	Execution time	Memory
1245153		datluong_04	Bank (IZhO14_bank)	C++20	100 / 100	287 ms	27468 KiB

bank

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define maxn 21
#define FOR(i , a , b) for(int i = a ; i <= b; i++)
#define FAST ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define BIT(mask , i) (mask >> i & 1)

ll a[maxn] , b[maxn] , cost[1 << maxn];

int dp[1 << maxn];

int main(){
    if(fopen("bank.in" , "r")){
        freopen("bank.in" , "r" , stdin);
        freopen("bank.out" , "w" , stdout);
    }

    FAST;
    int n , m;
    cin >> n >> m;
    FOR(i , 0 , n - 1) cin >> a[i];
    FOR(i , 0 , m - 1) cin >> b[i];
    ll sumA = 0; FOR(i , 0 , n - 1) sumA += a[i];
    ll sumB = 0; FOR(j , 0 , m - 1) sumB += b[j];
    if(sumA > sumB){cout << "NO\n"; return 0;}
    sort(a  , a + n  , greater<ll>());

    FOR(mask , 1 ,  (1 << m) - 1){
        int lsb = mask & (-mask);
        int j = __builtin_ctz(lsb);
        cost[mask] = cost[mask ^ lsb] + b[j];
    }

    FOR(mask , 0 , (1 << m) - 1) dp[mask] = -1;
    dp[0] = 0;
    int full_mask = (1 << m) - 1;

    unordered_map<ll,vector<ll>> mp;
    FOR(mask , 0 , (1 << m) - 1) mp[cost[mask]].push_back(mask);

    FOR(mask , 0 , (1 << m) - 1){
        int k = dp[mask];
        if(k < 0 || k == n) continue;
        ll need = a[k];
        auto it = mp.find(need);
        if(mp.end() == it) continue;
        for(int sub : it -> second){
            if( (sub & mask) == 0){
                int new_mask = mask | sub;
                dp[new_mask] = max(dp[new_mask] , k + 1);
            }
        }
    }

    bool ok = false;
    FOR(mask , 0 , (1 << m) - 1) if(dp[mask] == n){
        ok = true; 
        break;
    }
    cout << (ok ?"YES"  :"NO");
}

Compilation message (stderr)

bank.cpp: In function 'int main()':
bank.cpp:17:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         freopen("bank.in" , "r" , stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bank.cpp:18:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         freopen("bank.out" , "w" , stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 19 / 19
• Subtask 2: 25 / 25
• Subtask 3: 27 / 27
• Subtask 4: 29 / 29