Edit distance

#include <iostream>
#include <deque>
#include <algorithm>

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef std::string str;

using namespace std;

ll calcDistance(str a, str b, int n, int m) {
  if (n==-1) {
    return m+1;
  }
  if (m==-1) {
    return n+1;
  }
  return min(calcDistance(a, b, n-1, m) + 1,
      min(calcDistance(a, b, n, m-1) + 1,
      calcDistance(a, b, n-1, m-1) + (int)(a[n] != b[m])));
}

int main() {
    str a, b;
    cin >> a >> b;
    ll res = calcDistance(a, b, a.size()-1, b.size()-1);
    cout << res << endl;
}

Test 1

Verdict: UNKNOWN

Test 2

Verdict: UNKNOWN

Test 3

Verdict: UNKNOWN

Test 4

Verdict: UNKNOWN

Test 5

Verdict: UNKNOWN

Test 6

Verdict: UNKNOWN

Test 7

Verdict: UNKNOWN

Test 8

Verdict: UNKNOWN

Test 9

Verdict: UNKNOWN

Test 10

Verdict: UNKNOWN

Test 11

Verdict: UNKNOWN

Test 12

Verdict: UNKNOWN

Test 13

Verdict: UNKNOWN

Test 14

Verdict: UNKNOWN

Test 15

Verdict: UNKNOWN

Test 16

Verdict: UNKNOWN

Test 17

Verdict: UNKNOWN

Test 18

Verdict: UNKNOWN

Test 19

Verdict: UNKNOWN