[算法]动态规划之最长公共子序列

最长公共子序列

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<string.h>

#define N 5

int max(int a, int b, int c) {

    int ab = a>b ? a : b;
    return ab > c ? ab : c;

}

void solve(int *array1, int *array2, int n) {
    n = n + 1;

    int *pre = (int *)malloc(n * n * sizeof(int));
    int *dp = (int *)malloc(n * n * sizeof(int));
    int i;
    int j;
    int a, b, c;

    bzero((void *)dp, n * n * sizeof(int));
    bzero((void *)pre, n * n * sizeof(int));
  
    for(i = 1; i < n; i++) {
        for(j = 1; j < n; j++) {
            a = *(dp + (i -1)*n + j);
            b = *(dp + i * n + j - 1);
            c =  *(array1 + j - 1) == *(array2 + i - 1) ? *(dp + (i -1)*n + j - 1) + 1 : *(dp + (i -1)*n + j - 1);
            *(dp + i * n + j) = max(a, b, c); 
        } 
    }
    
    for(i = 0; i < n; i++) {
        for(j = 0; j < n; j++) {
            printf("%d	", *(dp + i * n + j));
        }
        printf("
");
    }

    free(dp);
    free(pre);
}

int main(char ** args) {
    srand((unsigned)time(NULL));
    
    int *array1 = (int *)malloc(N * sizeof(int));
    for(int i = 0; i < N; i++) {
        *(array1 + i) = rand() % N; 
        printf("%d	", *(array1 + i));
    }
    printf("
");

    int *array2 = (int *)malloc(N * sizeof(int));
    for(int i = 0; i < N; i++) {
        *(array2 + i) = rand() % N; 
        printf("%d	", *(array2 + i));
    }

    printf("
");
    printf("
");

    solve(array1, array2, N);

    free(array1);
    free(array2);
    return 0;
}