title: 583. Delete Operation for Two Strings
tags:
- dp
categories: leetcode
comments: false
class Solution {
public:
int minDistance(string word1, string word2) {
// e a t
// 0 1 2 3
//s 1 2 3 4
//e 2 1 2 3
//a 3 2 1 2
int n = word1.size(), m = word2.size();
vector<vector<int>> dp(n+1, vector<int>(m+1,0));
for(int i=0;i<n+1;++i) dp[i][0] = i;
for(int j=0;j<m+1;++j) dp[0][j] = j;
for(int i=1;i<n+1;i++){
for(int j = 1;j<m+1;j++){
if(word1[i-1] !=word2[j-1]) dp[i][j] = min( dp[i-1][j],dp[i][j-1] ) +1; // insert or delete
else dp[i][j] = dp[i-1][j-1];
}
}
return dp.back().back();
}
};
- time complexity
O(nm)
- space complexity
O(nm)