NYOJ题目5

NYOJ题目5Binary String Matching
Binary String Matching
描述
Given two strings A and B, whose alphabet consist only ‘0’ and ‘1’. Your task is only to tell how many times does A appear as a substring of B? For example, the text string B is ‘1001110110’ while the pattern string A is ‘11’, you should output 3, because the pattern A appeared at the posit
输入
The first line consist only one integer N, indicates N cases follows. In each case, there are two lines, the first line gives the string A, length (A) <= 10, and the second line gives the string B, length (B) <= 1000. And it is guaranteed that B is always longer than A.
输出
For each case, output a single line consist a single integer, tells how many times do B appears as a substring of A.
样例输入
3
11
1001110110
101
110010010010001
1010
110100010101011
样例输出
3
0
3

#include<stdio.h>
#include<string.h>
int main ()
{
    int n,m;
    char a[20],b[1010];
    scanf("%d",&n);
    getchar();
    while(n--)
    {
        int s=0,t=0;
        gets(a);
        gets(b);
        char *c=b;
        while(c!=NULL)
        {
            c=strstr(c+t,a);/*这里是关键，如果c不加1将会一直循环同一个数下去*/
            if(c==NULL) 
                break;
            t=1;
            s++;
        }
        printf("%d\n",s);
    }
    return 0;
} 

我在看c prime plus 的时候看到指针忽然就有想法这样写，只是当时用的是strchr（）也是这样的形式，当时我试了很久（指针用的不是特别好），然后也算是搞出来了，现在遇到这道题也就试试，发现也可以成功，于是就写出来了，比起之前用的暴力法要好很多，而且也算是开始领悟到了指针的神奇。