72. 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
这种题就是动态规划来做!f[i][j]代表word1的前i位变成word2的前j位需要多少步骤。
class Solution {
public:
int minDistance(string word1, string word2)
{
int row = word1.size();
int col = word2.size();
int f[row + 1][col + 1] = {0};
for (int i = 0; i <= row; i++)
{
for (int j = 0; j <= col; j++)
{
if (i == 0)
f[i][j] = j;
else if (j == 0)
f[i][j] = i;
else
{
if (word1[i - 1] == word2[j - 1])
f[i][j] = min(f[i-1][j-1], min(f[i][j-1], f[i-1][j]) + 1);
else
f[i][j] = min(f[i-1][j-1], min(f[i][j-1], f[i-1][j])) + 1;
}
}
}
return f[row][col];
}
};