int longestCommonSubsequence(string text1, string text2) {

string a = text1;

string b = text2;

int lena = a.size();

int lenb = b.size();

vector<vector<int>> dp(lena, vector<int>(lenb, 0));

int ans = 0;

for (int i = 0; i < lena; i++) {

for (int j = 0; j < lenb; j++) {

if (i == 0 || j == 0) {

if (a[i] == b[j]) dp[i][j] = 1;

if (i >= 1) dp[i][j] = max(dp[i-1][j], dp[i][j]);

if (j >= 1) dp[i][j] = max(dp[i][j-1], dp[i][j]);

ans = max(ans, dp[i][j]);

continue;

}

if (a[i] == b[j]) {

dp[i][j] = max(dp[i-1][j-1] + 1, dp[i][j]);

}

dp[i][j] = max(dp[i][j-1], dp[i][j]);

dp[i][j] = max(dp[i][j], dp[i-1][j]);

ans = max(ans, dp[i][j]);

}

}

return ans;

}