oj.uz

Submission #902519

# Submission time Handle Problem Language Result Execution time Memory
902519 2024-01-10T14:28:20 Z KN200711 Fancy Fence (CEOI20_fancyfence) C++14
0 / 100
 1 ms 348 KB 
# include <bits/stdc++.h>
# define ll long long
# define ld long double
# define fi first
# define se second
# define pll pair<ll, ll>
# define pdd pair<ld, ld>
# define pii pair<int, int>
using namespace std;

const ll MOD = 1e9 + 7;

int par[100001];
ll sz[100001], ans[100001];

ll C2(int a) {
	ll v = a * (a + 1ll) / 2ll;
	v %= MOD;
	return v;
}

int find(int a) {
	if(a == par[a]) return a;
	par[a] = find(par[a]);
	return par[a];
}

void merge(int a, int b, ll c) {
	a = find(a);
	b = find(b);
	if(a == b) return;
	ans[a] += ans[b];
	ans[a] %= MOD;
	
	ll G = C2(c) * (C2(sz[a]) + C2(sz[b]));
	G %= MOD;
	
	par[b] = a;
	sz[a] += sz[b];
	sz[a] %= MOD;
	ans[a] -= G;
	ans[a] %= MOD;
	
	G = C2(c) * (C2(sz[a]));
	G %= MOD;
	
	ans[a] += G;
	ans[a] %= MOD;
}

bool vis[100001];

int main() {
	int N;
	scanf("%d", &N);
	vector<pair<pii, int> > arr(N);
	for(int i=0;i<N;i++) {
		par[i] = i;
		scanf("%d", &arr[i].fi.fi);
	}
	for(int i=0;i<N;i++) {
		scanf("%d", &arr[i].fi.se);
		ans[i] = C2(arr[i].fi.fi) * C2(arr[i].fi.se);
		sz[i] = arr[i].fi.fi;
		ans[i] %= MOD;
		arr[i].se = i;
	}
	sort(arr.begin(), arr.end());
	for(int i=N-1;i>=0;i--) {
		int idx = arr[i].se;
		vis[idx] = 1;
		if(idx > 0 && vis[idx - 1]) merge(idx - 1, idx, arr[i].fi.fi);
		if(idx + 1 < N && vis[idx + 1]) merge(idx + 1, idx, arr[i].fi.fi);
	}
	if(ans[find(0)] < 0) ans[find(0)] += MOD;
	printf("%lld\n", ans[find(0)]);
}

Compilation message

fancyfence.cpp: In function 'int main()':
fancyfence.cpp:55:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |  scanf("%d", &N);
      |  ~~~~~^~~~~~~~~~
fancyfence.cpp:59:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |   scanf("%d", &arr[i].fi.fi);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~
fancyfence.cpp:62:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |   scanf("%d", &arr[i].fi.se);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Incorrect 1 ms 344 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Incorrect 1 ms 348 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 348 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Incorrect 1 ms 348 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #6
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Incorrect 1 ms 348 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Incorrect 1 ms 344 KB Output isn't correct
3 Halted 0 ms 0 KB -