Submission #766473

#	Time	Username	Problem	Language	Result	Execution time	Memory
766473		a_aguilo	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	406 ms	8636 KiB

bobek

#include<bits/stdc++.h>

using namespace std;

int N, mid;
long long M;
long long cost[40];

void smallM(){
	vector<long long int> dp(M+1, 0);
	dp[0] = 1;
	for(int match = 0; match < N; ++match){
		for(long long val = M; val > 0; --val){
			if(cost[match] <= val) dp[val] += dp[val - cost[match]];
		}
	}
	long long ans = 0;
	for(int i = 0; i <= M; ++i) ans += dp[i];
	cout << ans << endl;
}

int binarySearch(long long key, vector<long long>& V){
	//maximo i tal que V[i] <= key
	int lo = 0;
	int hi = (int)V.size()-1;
	int ans = -1;
	while(lo <= hi){
		int m = lo + (hi - lo)/2;
		if(V[m] <= key){
			ans = m;
			lo = m+1;
		}else hi = m-1;
	}
	return ans;
}

void print(vector<long long> & V){
	for(int x: V) cout << x << " ";
	cout << endl;
}

int main(){
	cin >> N >> M;
	for(int i = 0; i < N; ++i) cin >> cost[i];
	mid = N/2;
	vector<long long int>nums;
	for(int mask = 0; mask < (1 << mid); ++mask){
		long long sum = 0;
		for(int i = 0; i < mid; ++i){
			if(mask & (1 << i))sum += cost[i];
		}
		nums.push_back(sum);
	}
	sort(nums.begin(), nums.end());
	//print(nums);
	long long ans = 0;
	for(int mask = 0; mask < (1 << (N - mid)); ++mask){
		long long sum = 0;
		for(int i = 0; i < (N - mid); ++i){
			if(mask & (1 << i))sum += cost[i + mid];
		}
		long long pos = binarySearch(M - sum, nums);
		//cout << sum << " " << pos << endl;
		ans += pos + 1;
	}
	cout << ans << endl;
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10