[leetcode]Edit Distance

class Solution {
public:
    int minDistance(string word1, string word2) {
		int len1 = word1.length();
		int len2 = word2.length();
		if(len1 == 0) return len2;
		if(len2 == 0) return len1;
		int i,j;
		vector<vector<int> > dp(len1 + 1, vector<int>(len2 + 1));
		for(i = 0; i <= len1; i++)
		{
			dp[i][0] = i;
		}
		for(j = 0; j <= len2; j++)
		{
			dp[0][j] = j;
		}
		for(i = 1; i <= len1; i++)
		{
			for(j = 1; j <= len2; j++)
			{
				/*int cost = (word1[i-1] == word2[j - 1]) ? 0 : 1;
				dp[i][j] = min(dp[i-1][j-1]+cost,min(dp[i-1][j]+1,dp[i][j-1]+1));*/
				if(word1[i-1] == word2[j - 1])
				{
					dp[i][j] = min(dp[i-1][j-1],min(dp[i-1][j],dp[i][j-1]) + 1);
				}else{
					dp[i][j] = min(dp[i-1][j-1],min(dp[i-1][j],dp[i][j-1])) + 1;
				}
			}
		}
		return dp[len1][len2];
    }
};