oj.uz

Submission #257759

# Submission time Handle Problem Language Result Execution time Memory
257759 2020-08-04T17:46:09 Z updown1 Mate (COCI18_mate) C++14
80 / 100
 2000 ms 28432 KB 
/*
Code by @marlov
*/
#include <bits/stdc++.h>
using namespace std;

#define maxV 2005
#define MOD 1000000007

string s;
int Q;
long long pc[maxV][maxV];
long long dp[maxV][26];

int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin>>s;
	cin>>Q;
	//precomute pc[n][m] which is the nCm
	for(int i=0;i<maxV;i++){
		pc[i][0]=1;
		for(int j=1;j<i;j++){
			pc[i][j]=pc[i-1][j]+pc[i-1][j-1];
			pc[i][j]%=MOD;
		}
		pc[i][i]=1;
	}
	for(int i=0;i<26;i++){
		for(int j=s.length()-1;j>=0;j--){
			if(s[j]=='a'+i){
				dp[j][i]++;
			}
			if(j<s.length()-1){
				dp[j][i]+=dp[j+1][i];
			}
		}
	}
	long long tl;
	char fc,sc;
	for(int i=0;i<Q;i++){
		long long result=0;
		cin>>tl>>fc>>sc;
		for(int j=tl-2;j<s.length()-1;j++){
			if(s[j]==fc){
				result= (result + pc[j][tl-2]*(dp[j+1][sc-'a']))%MOD;
			}
		}
		cout<<result<<'\n';
	}
    return 0;
}

Compilation message

mate.cpp: In function 'int main()':
mate.cpp:33:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(j<s.length()-1){
       ~^~~~~~~~~~~~~
mate.cpp:43:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=tl-2;j<s.length()-1;j++){
                  ~^~~~~~~~~~~~~

Subtask #1
80.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 23168 KB Output is correct
2 Correct 18 ms 23168 KB Output is correct
3 Correct 18 ms 23168 KB Output is correct
4 Correct 22 ms 23168 KB Output is correct
5 Correct 61 ms 24088 KB Output is correct
6 Correct 68 ms 24284 KB Output is correct
7 Correct 52 ms 23928 KB Output is correct
8 Correct 49 ms 23896 KB Output is correct
9 Execution timed out 2090 ms 28368 KB Time limit exceeded
10 Execution timed out 2072 ms 28432 KB Time limit exceeded