Leetcode 72. Edit Distance (Hard) (cpp)

Leetcode 72. Edit Distance (Hard) (cpp)

Tag: Dynamic Programming, String

Difficulty: Hard

/*

72. Edit Distance (Hard)

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) {
		int row = word1.size(), col = word2.size();
		vector> t(row + 1, vector(col + 1, 0));
		for (int i = 0; i < row + 1; i++) {
			for (int j = 0; j < col + 1; j++) {
				if (i == 0) {
					t[i][j] = j;
				} else if (j == 0) {
					t[i][j] = i;
				} else if (word1[i - 1] == word2[j - 1]) {
					t[i][j] = t[i - 1][j - 1];
				} else {
					t[i][j] = min(min(t[i - 1][j - 1], t[i][j - 1]), t[i - 1][j]) + 1;
				}
			}
		}
		return t.back().back();
	}
};