Files
problemas-para-competicao-p…/longest-common-subsequence/src/ac.cpp
2025-12-09 21:26:27 -03:00

51 lines
1.1 KiB
C++

#include <bits/stdc++.h>
using namespace std;
int main()
{
int n, m;
cin >> n >> m;
string s1, s2;
cin >> s1 >> s2;
/*
let dp[i][j] represent the length of the longest common subsequence using the first i characters
of s1 and the first j characters of s2
if s1[i] == s2[j]
dp[i][j] = dp[i - 1][j - 1] + 1
else
dp[i][j] = max(dp[i - 1][j], dp[i][j - 1])
*/
vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (s1[i - 1] == s2[j - 1]) {
dp[i][j] = 1 + dp[i - 1][j - 1];
} else {
dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
}
}
}
int row = n, col = m;
string sub = "";
while (dp[row][col]) {
if (s1[row - 1] == s2[col - 1]) {
sub = string(1, s1[row - 1]) + sub;
row--, col--;
} else if (dp[row - 1][col] > dp[row][col - 1]) {
row--;
} else {
col--;
}
}
int size = dp[n][m];
cout << size << endl;
cout << sub << endl;
return 0;
}