LeetCode_Edit Distance

Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)

You have the following 3 operations permitted on a word:

a) Insert a character

b) Delete a character

c) Replace a character

　　

class Solution {

public:

    int minDistance(string word1, string word2) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        int m = word1.size();

    	int n = word2.size();

        vector<vector<int>>  table(m+1,vector<int>(n+1, 0));

		for(int i = 1; i <= n; i++) table[0][i] = i;

		for(int i = 1; i <= m; i++) table[i][0] = i;

		for(int i = 1; i <= m; i++)

			for(int j = 1; j <= n;j++)

			{

				int min1 = table[i-1][j] < table[i][j-1] ? table[i-1][j] : table[i][j-1];

                min1++;

				int min2 = word1[i-1] == word2[j-1] ? 0 : 1;

				min2 += table[i-1][j-1];

				table[i][j] = min1 < min2 ? min1 : min2;

			}

		return table[m][n];

    }

};

　　reference ：http://www.geeksforgeeks.org/dynamic-programming-set-5-edit-distance/