Edit Distance

Posted 2023-01-20 IIcyZhao

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 w1_size = word1.size();
        int w2_size = word2.size();
        int max_size = std::max(w1_size, w2_size) + 1;
        vector<vector<int> > record;
        for (int i = 0; i <= w1_size; ++i) 
            record.push_back(vector<int>(w2_size+1, max_size));
            record[i][0] = i;
        
        for (int i = 0; i <= w2_size; ++i) 
            record[0][i] = i;
        
        for (int i = 1; i <= w1_size; ++i) 
            for (int j = 1; j <= w2_size; ++j) 
                if (word1[i-1] == word2[j-1])   //注意下标,从第一个字符word1[0] 与 word2[0]
                    record[i][j] = record[i-1][j-1];
                 else 
                    if (record[i-1][j] + 1 < record[i][j]) 
                       record[i][j] = record[i-1][j] + 1;
                     
                    if (record[i][j-1] + 1 < record[i][j]) 
                        record[i][j] = record[i][j-1] + 1;
                    
                    if (record[i-1][j-1] + 1 < record[i][j]) 
                        record[i][j] = record[i-1][j-1] + 1;
                    
                
            
        
        return record[w1_size][w2_size];
    
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