code/dynamicProgramming/editDistance.cc

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Last update: 2020-10-28 19:21:59+01:00

Depends on

code/template.cc

Verified with

tests/aoj/edit_distance.test.cpp

Code

#include "../template.hh"
const int inf = 1e9;

int editDistance(const string& a, const string& b) {
  vvi dp(SZ(a) + 1, vi(SZ(b) + 1, inf));
  F0R(i, SZ(a) + 1) {
    F0R(j, SZ(b) + 1) {
      if(!i) dp[i][j] = j;
      else if(!j) dp[i][j] = i;
      else {
        dp[i][j] = 1 + min({dp[i - 1][j - 1],
                            dp[i][j - 1], dp[i - 1][j]});
        if(a[i - 1] == b[j - 1]) ckmin(dp[i][j], dp[i - 1][j - 1]);
      }
    }
  }
  return dp[SZ(a)][SZ(b)];
}

#line 1 "code/template.cc"
// this line is here for a reason
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
#define fi first
#define se second
#define eb emplace_back
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define endl '\n'
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define SZ(x) (int)(x).size()
#define FOR(a, b, c) for (auto a = (b); (a) < (c); ++(a))
#define F0R(a, b) FOR (a, 0, (b))
template <typename T>
bool ckmin(T& a, const T& b) { return a > b ? a = b, true : false; }
template <typename T>
bool ckmax(T& a, const T& b) { return a < b ? a = b, true : false; }
#ifndef DEBUG
#define DEBUG 0
#endif
#define dout if (DEBUG) cerr
#define dvar(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
#line 2 "code/dynamicProgramming/editDistance.cc"
const int inf = 1e9;

int editDistance(const string& a, const string& b) {
  vvi dp(SZ(a) + 1, vi(SZ(b) + 1, inf));
  F0R(i, SZ(a) + 1) {
    F0R(j, SZ(b) + 1) {
      if(!i) dp[i][j] = j;
      else if(!j) dp[i][j] = i;
      else {
        dp[i][j] = 1 + min({dp[i - 1][j - 1],
                            dp[i][j - 1], dp[i - 1][j]});
        if(a[i - 1] == b[j - 1]) ckmin(dp[i][j], dp[i - 1][j - 1]);
      }
    }
  }
  return dp[SZ(a)][SZ(b)];
}