HDU1711/HDU1686 KMP 

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 int T,n,m;
 4 int a[1000005],b[10005];
 5 int nxt[10005];
 6 
 7 
 8 void getnxt(){
 9     int j = 0,k = -1;
10     while(j < m){
11         if (k == -1 || b[j] == b[k]){
12             if (b[++j] == b[++k]){
13                 nxt[j] = nxt[k];
14             }else{
15                 nxt[j] = k;
16             }
17         }else{
18             k = nxt[k];
19         }
20     }
21 }
22 
23 int kmp(){
24     getnxt();
25     int i,j = i= 0;
26     while(i < n && j < m){
27         if (j == -1 || a[i] == b[j]){
28             i++;
29             j++;
30         }else{
31             j = nxt[j];
32         }
33     }
34     if (j == m) return i-j + 1;
35         else return -1;
36 }
37 
38 int main(){
39     scanf("%d",&T);
40     while(T--){
41         memset(nxt,-1,sizeof(nxt));
42         scanf("%d%d",&n,&m);
43         for (int i = 0;i < n;++i) scanf("%d",a+i);
44         for (int i = 0;i < m;++i) scanf("%d",b+i);
45 
46         printf("%d\n",kmp());
47     }
48     return 0;
49 }
View Code

上面是1711，下面是1686

#include <bits/stdc++.h>
using namespace std;
int nxt[10010];
char a[1000005];
char b[10010];
int n,m,T;

void getnext(){
    memset(nxt,-1,sizeof(nxt));
    int j = -1;
    nxt[0] = -1;
    int i = 0;
    while(i < m){
        while(j != -1 && b[j] != b[i]) j = nxt[j];
        i++;j++;
        nxt[i] = j;
    }
}

int kmp()
{
    int cnt = 0;
    int i,j = i = 0;
    while(i < n){
        while(j != -1 && b[j] != a[i]) j = nxt[j];
        i++;j++;
        if (j >= m){
            cnt++;
            j = nxt[j];
        }
    }
    return cnt;
}


int main()
{
    scanf("%d",&T);
    while(T--){
        scanf("%s",b);
        m = strlen(b);
        scanf("%s",a);
        n = strlen(a);
        getnext();
        printf("%d\n",kmp());
    }
}
View Code

 

posted @ 2018-08-24 14:30  mizersy  阅读(121)  评论(0)  编辑  收藏  举报