Submission #537889

#	Time	Username	Problem	Language	Result	Execution time	Memory
537889		nicolexxuu	Bank (IZhO14_bank)	C++14	100 / 100	118 ms	8540 KiB

bank

//#include <bits/stdc++.h>
//#define MAXN 21
//using namespace std;
//
//int a[MAXN], b[MAXN];
//bool possible[MAXN][1 << MAXN];
//vector<int> combos[MAXN * 1000];
//int N, M;
//
//int main() {
//	ios_base::sync_with_stdio(0); 
//	cin.tie(NULL);
//	cin >> N >> M;
//	for(int i = 0; i < N; i++) cin >> a[i];
//	for(int i = 0; i < M; i++) cin >> b[i];
//	
//	for(int mask = 0; mask < (1 << M); mask++) {
//		int sum = 0;
//		for(int i = 0; i < M; i++) {
//			if(mask & (1 << i)) sum += b[i];
//		}
//		combos[sum].push_back(mask);
//	}
//	
//	possible[0][0] = true;
//	for(int i = 0; i < N; i++) {
//		for(int mask = 1; mask < (1 << M); mask++) {
//			for(int combo : combos[a[i]]) {
//				if((combo & mask) == combo) possible[i+1][mask] |= possible[i][mask - combo];
//			}
//		}
//	}
//	
//	bool res = false;
//	for(int i = 0; i < (1 << M); i++) res |= possible[N][i];
//	if(res) cout << "YES\n";
//	else cout << "NO\n";
//}

#include <iostream>
#include <vector>

using std::cout;
using std::endl;
using std::vector;

int main() {
	int people_num;
	int note_num;
	std::cin >> people_num >> note_num;
	vector<int> people(people_num);
	vector<int> banknotes(note_num);
	for (int& p : people) {
		std::cin >> p;
	}
	for (int& b : banknotes) {
		std::cin >> b;
	}

	vector<int> leftover(1 << note_num, -1);
	vector<int> people_covered(1 << note_num, -1);
	leftover[0] = 0;
	people_covered[0] = 0;
	for (int s = 0; s < (1 << note_num); s++) {
		for (int last = 0; last < note_num; last++) {
			if ((s & (1 << last)) == 0) {
				continue;
			}
			int prev = s & ~(1 << last);
			if (people_covered[prev] == -1) {
				continue;
			}

			int new_amt = leftover[prev] + banknotes[last];
			// the salary of the current person we're going to try to pay
			int curr_target = people[people_covered[prev]];
			// if it's still not enough, just increment the leftover pile
			if (new_amt < curr_target) {
				people_covered[s] = people_covered[prev];
				leftover[s] = new_amt;
			}
			/*
			 * or it's exactly right, in which case reset the leftover count
			 * and increment the covered amount
			 */
			else if (new_amt == curr_target) {
				people_covered[s] = people_covered[prev] + 1;
				leftover[s] = 0;
			}
		}
		// we've covered all the people!
		if (people_covered[s] == people_num) {
			cout << "YES" << endl;
			return 0;
		}
	}
	cout << "NO" << endl;
}

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