leetcode-solutions/72.cpp at main · juneguo257/leetcode-solutions · GitHub

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#include <iostream>

using namespace std;

int sim(int (*dp)[501], string &word1, string &word2, int p1, int p2, int ops)
{
    if (dp[p1][p2] != 0)
    {
        return dp[p1][p2] + ops;
    }
    else if (p1 >= word1.length() && p2 >= word2.length())
    {
        dp[p1][p2] = 0;
    }
    else if (p1 >= word1.length())
    {
        dp[p1][p2] = sim(dp, word1, word2, p1, p2 + 1, ops + 1) - ops; // add to word1
    }
    else if (p2 >= word2.length())
    {
        dp[p1][p2] = sim(dp, word1, word2, p1 + 1, p2, ops + 1) - ops; // remove from word1
    }
    else if (word1[p1] == word2[p2])
    {
        dp[p1][p2] = sim(dp, word1, word2, p1 + 1, p2 + 1, ops) - ops; // match!
    }
    else
    {
        int addW1 = sim(dp, word1, word2, p1, p2 + 1, ops + 1);         // add to word1
        int removeW1 = sim(dp, word1, word2, p1 + 1, p2, ops + 1);      // remove from word1
        int replaceW1 = sim(dp, word1, word2, p1 + 1, p2 + 1, ops + 1); // replace in word1
        dp[p1][p2] = std::min(addW1, std::min(removeW1, replaceW1)) - ops;
    }
    return dp[p1][p2] + ops;
}

int minDistance(string word1, string word2)
{
    int dp[501][501] = {{0}};
    return sim(dp, word1, word2, 0, 0, 0);
}

int main()
{
    cout << minDistance("horse", "ros") << endl;
    return 0;
}