oj.uz

Submission #31223

# Submission time Handle Problem Language Result Execution time Memory
31223 2017-08-14T11:57:11 Z gs14004 Žarulje (COI15_zarulje) C++14
100 / 100
 399 ms 12772 KB 
#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pi;
typedef long long lint;
const int MAXN = 200005;
const int mod = 1e9 + 7;

lint ipow(lint x, lint p){
	lint ret = 1, piv = x % mod;
	while(p){
		if(p&1) ret *= piv;
		piv *= piv;
		ret %= mod;
		piv %= mod;
		p >>= 1;
	}
	return ret % mod;
}

int n, k, a[MAXN];
int l[MAXN], r[MAXN];
lint fact[MAXN], invf[MAXN], ans[MAXN];
pi b[MAXN];

lint bino(int x, int y){
	return fact[x] * (invf[y] * invf[x-y] % mod) % mod;
}

int main(){
	scanf("%d %d",&n,&k);
	fact[0] = invf[0] = 1;
	for(int i=0; i<n; i++){
		fact[i + 1] = fact[i] * (i + 1) % mod;
		invf[i + 1] = ipow(fact[i + 1], mod - 2);
		scanf("%d",&a[i]);
		b[i] = pi(a[i], i);
	}
	stack<int> stk;
	for(int i=0; i<n; i++){
		while(!stk.empty() && a[stk.top()] > a[i]){
			r[stk.top()] = i;
			stk.pop();
		}
		stk.push(i);
	}
	while(!stk.empty()){
		r[stk.top()] = n;
		stk.pop();
	}
	for(int i=n-1; i>=0; i--){
		while(!stk.empty() && a[stk.top()] > a[i]){
			l[stk.top()] = i;
			stk.pop();
		}
		stk.push(i);
	}
	while(!stk.empty()){
		l[stk.top()] = -1;
		stk.pop();
	}
	sort(b, b+n);
	fill(ans, ans + n, 1);
	for(int i=0; i<n; ){
		int e = i;
		while(e < n && b[e].first == b[i].first) e++;
		vector<pi> swp;
		for(int j=i; j<e; j++){
			int pos = b[j].second;
			swp.push_back(pi(l[pos], 2));
			swp.push_back(pi(pos, -2));
			swp.push_back(pi(pos + 1, 1));
			swp.push_back(pi(r[pos] + 1, -1));
		}
		int cnt1 = 0, cnt2 = 0;
		sort(swp.begin(), swp.end());
		for(int i=0; i<swp.size(); ){
			int e = i;
			while(e < swp.size() && swp[e].first == swp[i].first){
				if(abs(swp[e].second) == 2) cnt2 += swp[e].second / 2;
				else cnt1 += swp[e].second;
				e++;
			}
			if(e < swp.size()){
				lint k = bino(cnt1 + cnt2, cnt1);
				int st = swp[i].first;
				int ed = swp[e].first;
				st = max(st, 0);
				if(st < ed){
					ans[st] *= k;
					ans[ed] *= ipow(k, mod - 2);
					ans[st] %= mod;
					ans[ed] %= mod;
				}
			}
			i = e;
		}
		i = e;
	}
	for(int i=0; i<n; i++){
		ans[i+1] *= ans[i];
		ans[i+1] %= mod;
	}
	for(int i=0; i<k; i++){
		int x;
		scanf("%d",&x);
		printf("%lld\n", ans[x-1]);
	}
}

Compilation message

zarulje.cpp: In function 'int main()':
zarulje.cpp:76:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<swp.size(); ){
                 ^
zarulje.cpp:78:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    while(e < swp.size() && swp[e].first == swp[i].first){
            ^
zarulje.cpp:83:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(e < swp.size()){
         ^
zarulje.cpp:30:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&k);
                      ^
zarulje.cpp:35:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
                    ^
zarulje.cpp:105:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x);
                 ^

Subtask #1
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 10620 KB Output is correct
2 Correct 0 ms 10620 KB Output is correct
3 Correct 3 ms 10620 KB Output is correct
4 Correct 3 ms 10620 KB Output is correct
5 Correct 3 ms 10620 KB Output is correct
6 Correct 3 ms 10620 KB Output is correct

Subtask #2
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 139 ms 10620 KB Output is correct
2 Correct 256 ms 12772 KB Output is correct
3 Correct 313 ms 10956 KB Output is correct
4 Correct 319 ms 10620 KB Output is correct
5 Correct 329 ms 10620 KB Output is correct
6 Correct 283 ms 10620 KB Output is correct
7 Correct 306 ms 10620 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 10620 KB Output is correct
2 Correct 0 ms 10620 KB Output is correct
3 Correct 3 ms 10620 KB Output is correct
4 Correct 3 ms 10620 KB Output is correct
5 Correct 3 ms 10620 KB Output is correct
6 Correct 3 ms 10620 KB Output is correct
7 Correct 139 ms 10620 KB Output is correct
8 Correct 256 ms 12772 KB Output is correct
9 Correct 313 ms 10956 KB Output is correct
10 Correct 319 ms 10620 KB Output is correct
11 Correct 329 ms 10620 KB Output is correct
12 Correct 283 ms 10620 KB Output is correct
13 Correct 306 ms 10620 KB Output is correct
14 Correct 16 ms 10620 KB Output is correct
15 Correct 186 ms 10620 KB Output is correct
16 Correct 333 ms 12772 KB Output is correct
17 Correct 349 ms 10956 KB Output is correct
18 Correct 399 ms 10620 KB Output is correct
19 Correct 399 ms 10620 KB Output is correct
20 Correct 399 ms 10620 KB Output is correct
21 Correct 396 ms 10620 KB Output is correct