字符串编辑距离

 1 #include <iostream>
 2 using namespace std;
 3 
 4 #include <string.h>
 5 
 6 #define N 100
 7 int matrix[N][N];
 8 int penalty = 10;
 9 
10 int MinOf3(int x, int y, int z) {
11     x = x < y ? x : y;
12     return x < z ? x : z;
13 }
14 
15 int MinOf2(int x, int y)
16 {
17     return x < y ? x : y;
18 }
19 int Distance(const char * p1, const char * p2)
20 {
21     int l1 = strlen(p1);
22     int l2 = strlen(p2);
23     int i, j;
24     matrix[0][0] = 0;
25     for (i = 1; i <= l1; ++i) {
26         matrix[i][0] = i * penalty;
27     }
28     for (j = 1; j <= l2; ++j) {
29         matrix[0][j] = j * penalty;
30     }
31     
32     for (i = 1; i <= l1; ++i) {
33         for (j = 1; j <= l2; ++j) {
34             if (p1[i - 1] == p2[j - 1]) {
35                 matrix[i][j] = matrix[i - 1][j - 1];
36             } else {
37             matrix[i][j] = MinOf3(matrix[i - 1][j], matrix[i][j - 1],
38                             matrix[i - 1][j - 1]) + penalty;
39             }
40         }
41     }
42 
43     return matrix[l1][l2];
44 }
45 
46 void Print(int n1, int n2)
47 {
48     int i, j;
49     for (i = 0; i <= n1; ++i) {
50         for (j = 0; j <= n2; ++j) {
51             printf("%3d", matrix[i][j]);
52         }
53         printf("\n");
54     }
55 }
56 
57 int main()
58 {
59     cout << Distance("abc", "ab") << endl;
60     Print(3, 2);
61 
62     return 0;
63 }