oj.uz

Submission #412888

# Submission time Handle Problem Language Result Execution time Memory
412888 2021-05-27T18:29:58 Z amoo_safar Sparklers (JOI17_sparklers) C++17
50 / 100
 302 ms 16256 KB 
// vaziat meshki-ghermeze !
#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'

using namespace std;

typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;

const ll Mod = 1000000007LL;
const int N = 2e3 + 10;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;

int n, k;
ll X[N];
vector<ll> A, B;
ll psA[N], psB[N];

int dp[N][N];

bool Check(ll T){
	if(T > 1000000000)
		return true;
	A = {T};
	B = {};
	for(int i = k + 1; i <= n; i++){
		A.pb(X[i - 1] - X[i]);
		A.pb(T);
	}
	for(int i = k - 1; i >= 1; i--){
		B.pb(X[i] - X[i + 1]);
		B.pb(T);
	}
	psA[0] = 0;
	for(int i = 1; i <= (int) A.size(); i++)
		psA[i] = psA[i - 1] + A[i - 1];
	psB[0] = 0;
	for(int i = 1; i <= (int) B.size(); i++)
		psB[i] = psB[i - 1] + B[i - 1];

	// memset(dp, 0, sizeof dp);
	int sa = A.size(), sb = B.size();
	int pa = 0, pb = 0;
	while((pa < sa) || (pb < sb)){
		ll nw = psA[pa] + psB[pb];
		if(nw < 0) return false;
		if(pa == sa){
			pb ++;
			continue;
		}
		if(pb == sb){
			pa ++;
			continue;
		}
		int des = pa;
		for(int nx = pa + 1; nx <= sa; nx ++){
			if(psA[nx] + psB[pb] < 0) break;
			if(psA[pa] <= psA[nx]){
				des = nx;
				break;
			}
		}
		if(des > pa){
			pa = des;
			continue;
		}
		des = pb;
		for(int nx = pb + 1; nx <= sb; nx ++){
			if(psA[pa] + psB[nx] < 0) break;
			if(psB[pb] <= psB[nx]){
				des = nx;
				break;
			}
		}
		if(des > pb){
			pb = des;
			continue;
		}
		pa ++;
	}

	return psA[sa] + psB[sb] >= 0;
}

bool Check2(ll T){
	if(T > 1000000000)
		return true;
	A = {T};
	B = {};
	for(int i = k + 1; i <= n; i++){
		A.pb(X[i - 1] - X[i]);
		A.pb(T);
	}
	for(int i = k - 1; i >= 1; i--){
		B.pb(X[i] - X[i + 1]);
		B.pb(T);
	}
	psA[0] = 0;
	for(int i = 1; i <= (int) A.size(); i++)
		psA[i] = psA[i - 1] + A[i - 1];
	psB[0] = 0;
	for(int i = 1; i <= (int) B.size(); i++)
		psB[i] = psB[i - 1] + B[i - 1];
 
	memset(dp, 0, sizeof dp);
	int sa = A.size(), sb = B.size();
	dp[0][0] = 1;
	for(int i = 0; i <= sa; i++){
		for(int j = 0; j <= sb; j++){
			if(i + j == 0) continue;
			if(psA[i] + psB[j] < 0) continue;
			if(i)
				dp[i][j] |= dp[i - 1][j];
			if(j)
				dp[i][j] |= dp[i][j - 1];
		}
	}
	return dp[sa][sb];
}


int main(){
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ll T;
	cin >> n >> k >> T;
	for(int i = 1; i <= n; i++)
		cin >> X[i];

	int mid, L = -1, R = 1000000000;
	while(L + 1 < R){
		mid = (L + R) >> 1;
		if(Check(2ll * T * mid) != Check2(2ll * T * mid)){
			if(Check(2ll * T * mid))
				assert(false);
		}
		if(Check2(2ll * T * mid))
			R = mid;
		else L = mid;
	}
	cout << R << '\n';
	return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 125 ms 16076 KB Output is correct
2 Correct 124 ms 16076 KB Output is correct
3 Correct 120 ms 16108 KB Output is correct
4 Correct 127 ms 16076 KB Output is correct
5 Correct 129 ms 16112 KB Output is correct
6 Correct 128 ms 16112 KB Output is correct
7 Correct 126 ms 16120 KB Output is correct
8 Correct 127 ms 16108 KB Output is correct
9 Correct 133 ms 16108 KB Output is correct
10 Correct 131 ms 16060 KB Output is correct
11 Correct 129 ms 16004 KB Output is correct
12 Correct 131 ms 16124 KB Output is correct
13 Correct 131 ms 16124 KB Output is correct
14 Correct 126 ms 16112 KB Output is correct
15 Correct 128 ms 16112 KB Output is correct
16 Correct 127 ms 16108 KB Output is correct
17 Correct 127 ms 16108 KB Output is correct
18 Correct 128 ms 16076 KB Output is correct
19 Correct 123 ms 16076 KB Output is correct
20 Correct 14 ms 16072 KB Output is correct
21 Correct 122 ms 16120 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 125 ms 16076 KB Output is correct
2 Correct 124 ms 16076 KB Output is correct
3 Correct 120 ms 16108 KB Output is correct
4 Correct 127 ms 16076 KB Output is correct
5 Correct 129 ms 16112 KB Output is correct
6 Correct 128 ms 16112 KB Output is correct
7 Correct 126 ms 16120 KB Output is correct
8 Correct 127 ms 16108 KB Output is correct
9 Correct 133 ms 16108 KB Output is correct
10 Correct 131 ms 16060 KB Output is correct
11 Correct 129 ms 16004 KB Output is correct
12 Correct 131 ms 16124 KB Output is correct
13 Correct 131 ms 16124 KB Output is correct
14 Correct 126 ms 16112 KB Output is correct
15 Correct 128 ms 16112 KB Output is correct
16 Correct 127 ms 16108 KB Output is correct
17 Correct 127 ms 16108 KB Output is correct
18 Correct 128 ms 16076 KB Output is correct
19 Correct 123 ms 16076 KB Output is correct
20 Correct 14 ms 16072 KB Output is correct
21 Correct 122 ms 16120 KB Output is correct
22 Correct 186 ms 16164 KB Output is correct
23 Correct 143 ms 16076 KB Output is correct
24 Correct 139 ms 16076 KB Output is correct
25 Correct 147 ms 16180 KB Output is correct
26 Correct 200 ms 16168 KB Output is correct
27 Correct 214 ms 16180 KB Output is correct
28 Correct 302 ms 16256 KB Output is correct
29 Correct 255 ms 16196 KB Output is correct
30 Correct 210 ms 16076 KB Output is correct
31 Correct 234 ms 16196 KB Output is correct
32 Correct 262 ms 16076 KB Output is correct
33 Correct 269 ms 16164 KB Output is correct
34 Correct 190 ms 16172 KB Output is correct
35 Correct 249 ms 16192 KB Output is correct
36 Correct 174 ms 16176 KB Output is correct
37 Correct 171 ms 16176 KB Output is correct
38 Correct 255 ms 16180 KB Output is correct
39 Correct 151 ms 16168 KB Output is correct
40 Correct 267 ms 16172 KB Output is correct

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 125 ms 16076 KB Output is correct
2 Correct 124 ms 16076 KB Output is correct
3 Correct 120 ms 16108 KB Output is correct
4 Correct 127 ms 16076 KB Output is correct
5 Correct 129 ms 16112 KB Output is correct
6 Correct 128 ms 16112 KB Output is correct
7 Correct 126 ms 16120 KB Output is correct
8 Correct 127 ms 16108 KB Output is correct
9 Correct 133 ms 16108 KB Output is correct
10 Correct 131 ms 16060 KB Output is correct
11 Correct 129 ms 16004 KB Output is correct
12 Correct 131 ms 16124 KB Output is correct
13 Correct 131 ms 16124 KB Output is correct
14 Correct 126 ms 16112 KB Output is correct
15 Correct 128 ms 16112 KB Output is correct
16 Correct 127 ms 16108 KB Output is correct
17 Correct 127 ms 16108 KB Output is correct
18 Correct 128 ms 16076 KB Output is correct
19 Correct 123 ms 16076 KB Output is correct
20 Correct 14 ms 16072 KB Output is correct
21 Correct 122 ms 16120 KB Output is correct
22 Correct 186 ms 16164 KB Output is correct
23 Correct 143 ms 16076 KB Output is correct
24 Correct 139 ms 16076 KB Output is correct
25 Correct 147 ms 16180 KB Output is correct
26 Correct 200 ms 16168 KB Output is correct
27 Correct 214 ms 16180 KB Output is correct
28 Correct 302 ms 16256 KB Output is correct
29 Correct 255 ms 16196 KB Output is correct
30 Correct 210 ms 16076 KB Output is correct
31 Correct 234 ms 16196 KB Output is correct
32 Correct 262 ms 16076 KB Output is correct
33 Correct 269 ms 16164 KB Output is correct
34 Correct 190 ms 16172 KB Output is correct
35 Correct 249 ms 16192 KB Output is correct
36 Correct 174 ms 16176 KB Output is correct
37 Correct 171 ms 16176 KB Output is correct
38 Correct 255 ms 16180 KB Output is correct
39 Correct 151 ms 16168 KB Output is correct
40 Correct 267 ms 16172 KB Output is correct
41 Runtime error 3 ms 460 KB Execution killed with signal 11
42 Halted 0 ms 0 KB -