CSES-1639 Edit Distance

#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define fi first
#define se second
#define INF LONG_LONG_MAX/1000
#define WA() cin.tie(0)->sync_with_stdio(0)
#define all(x) (x).begin(), (x).end()
#define int long long
#define PII pair<int, int>

signed main() { WA();
    string a, b; cin >> a >> b;
    int n = a.size(), m = b.size();
    vector<vector<int>> dp(n+1, vector<int>(m+1));
    for (int i = 1; i <= n; i++) dp[i][0] = i;
    for (int i = 1; i <= m; i++) dp[0][i] = i;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            if (a[i-1] == b[j-1]) dp[i][j] = dp[i-1][j-1];
            else dp[i][j] = min({dp[i-1][j-1], dp[i-1][j], dp[i][j-1]})+1;
        }
    }
    cout << dp[n][m] << '\n';
}