[算法]动态规划之最长公共子序列

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<time.h>
 4 #include<string.h>
 5 
 6 #define N 5
 7 
 8 int max(int a, int b, int c) {
 9 
10     int ab = a>b ? a : b;
11     return ab > c ? ab : c;
12 
13 }
14 
15 void solve(int *array1, int *array2, int n) {
16     n = n + 1;
17 
18     int *pre = (int *)malloc(n * n * sizeof(int));
19     int *dp = (int *)malloc(n * n * sizeof(int));
20     int i;
21     int j;
22     int a, b, c;
23 
24     bzero((void *)dp, n * n * sizeof(int));
25     bzero((void *)pre, n * n * sizeof(int));
26   
27     for(i = 1; i < n; i++) {
28         for(j = 1; j < n; j++) {
29             a = *(dp + (i -1)*n + j);
30             b = *(dp + i * n + j - 1);
31             c =  *(array1 + j - 1) == *(array2 + i - 1) ? *(dp + (i -1)*n + j - 1) + 1 : *(dp + (i -1)*n + j - 1);
32             *(dp + i * n + j) = max(a, b, c); 
33         } 
34     }
35     
36     for(i = 0; i < n; i++) {
37         for(j = 0; j < n; j++) {
38             printf("%d\t", *(dp + i * n + j));
39         }
40         printf("\n");
41     }
42 
43     free(dp);
44     free(pre);
45 }
46 
47 int main(char ** args) {
48     srand((unsigned)time(NULL));
49     
50     int *array1 = (int *)malloc(N * sizeof(int));
51     for(int i = 0; i < N; i++) {
52         *(array1 + i) = rand() % N; 
53         printf("%d\t", *(array1 + i));
54     }
55     printf("\n");
56 
57     int *array2 = (int *)malloc(N * sizeof(int));
58     for(int i = 0; i < N; i++) {
59         *(array2 + i) = rand() % N; 
60         printf("%d\t", *(array2 + i));
61     }
62 
63     printf("\n");
64     printf("\n");
65 
66     solve(array1, array2, N);
67 
68     free(array1);
69     free(array2);
70     return 0;
71 }