Submission #398796

#	Time	Username	Problem	Language	Result	Execution time	Memory
398796		nikatamliani	Selling RNA Strands (JOI16_selling_rna)	C++14	35 / 100	1600 ms	163472 KiB

selling_rna

#include "bits/stdc++.h"
using namespace std;
const int N = 2e5+10, p = 37, MOD = 1e9+7;
string s[N];
int n, m, P[N];
bool check(const string &a, const string &b) { // a >= b ? true : false
	int mini = min((int)a.size(), (int)b.size());
	for(int i = 0; i < mini; ++i) {
		if(a[i] != b[i]) {
			return a[i] > b[i];
		}
	}
	return mini == (int)b.size();
}
bool is_prefix(const string &a, const string &b) {
	if((int)a.size() > (int)b.size()) {
		return false;
	}
	for(int i = 0; i < (int)a.size(); ++i) {
		if(a[i] != b[i]) {
			return false;
		}
	}
	return true;
}
int find_first(const string &p) {
	int l = 1, r = n, pos = n+1;
	while(r >= l) {
		int m = l + r >> 1;
		if(check(s[m], p)) {
			r = m - 1;
			pos = m;
		} else {
			l = m + 1;
		}
	}
	return pos;
}
int find_last(int start, const string &p) {
	int l = start, r = n, pos = 0;
	while(r >= l) {
		int m = l + r >> 1;
		if(is_prefix(p, s[m])) {
			pos = m;
			l = m + 1;
		} else {
			r = m - 1;
		}
	}
	return pos;
}
int count(const vector<int> &v, int x) {
	if(v.empty()) return 0;
	int l = 0, r = (int)v.size()-1, pos = -1;
	while(r >= l) {
		int m = l + r >> 1;
		if(v[m] <= x) {
			pos = m;
			l = m + 1;
		} else {
			r = m - 1;
		}
	}
	return pos+1;
}
int count(const vector<int> &v, int L, int R) {
	return count(v, R) - count(v, L-1);
}
int id[256];
map<int, vector<int>> ids;
int main() {
	P[0] = 1;
	for(int i = 1; i < N; ++i) {
		P[i] = (long long)P[i - 1] * p % MOD;
	}
	id['A'] = 1;
	id['U'] = 2;
	id['G'] = 3;
	id['C'] = 4;
	ios::sync_with_stdio(0); cin.tie(0);
	cin >> n >> m;
	for(int i = 1; i <= n; ++i) {
		cin >> s[i];
	}
	sort(s+1, s+n+1);
	for(int i = 1; i <= n; ++i) {
		int hash = 0;
		for(int x = (int)s[i].size() - 1; x >= 0; --x) {
			hash = ((long long)hash * p + id[s[i][x]]) % MOD;
			ids[hash].push_back(i);
		}
	}
	for(int i = 1; i <= m; ++i) {
		string p, q; cin >> p >> q;
		int L = n+1, R = 0;
		L = find_first(p);
		if(!is_prefix(p, s[L])) {
			cout << "0\n";
			continue;
		}
		R = find_last(L, p); 
		assert(is_prefix(p, s[R]));
		int hash = 0;
		for(int x = 0; x < (int)q.size(); ++x) {
			hash = (hash + (long long)P[x] * id[q[x]]) % MOD;
		}
		if(L > R) {
			cout << "0\n";
			continue;
		}
		cout << count(ids[hash], L, R) << '\n';
	}
}

Compilation message (stderr)

selling_rna.cpp: In function 'int find_first(const string&)':
selling_rna.cpp:29:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   29 |   int m = l + r >> 1;
      |           ~~^~~
selling_rna.cpp: In function 'int find_last(int, const string&)':
selling_rna.cpp:42:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   42 |   int m = l + r >> 1;
      |           ~~^~~
selling_rna.cpp: In function 'int count(const std::vector<int>&, int)':
selling_rna.cpp:56:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   56 |   int m = l + r >> 1;
      |           ~~^~~
selling_rna.cpp: In function 'int main()':
selling_rna.cpp:89:44: warning: array subscript has type 'char' [-Wchar-subscripts]
   89 |    hash = ((long long)hash * p + id[s[i][x]]) % MOD;
      |                                            ^
selling_rna.cpp:105:44: warning: array subscript has type 'char' [-Wchar-subscripts]
  105 |    hash = (hash + (long long)P[x] * id[q[x]]) % MOD;
      |                                            ^

• Subtask 1: 10 / 10
• Subtask 2: 0 / 25
• Subtask 3: 25 / 25
• Subtask 4: 0 / 40