1953 Problem B #103. 子串查找

#include<stdio.h>
#include<string.h>
main()
{
char a[100],b[100];
int n,k,i;
gets(a);
gets(b);
n=0;
for(k=0;k<=strlen(a)-strlen(b);k++)
{
for(i=0;b[i]!=0;i++)
if(b[i]!=a[k+i]) break;
if(b[i]==0) n=n+1;
}
printf("%d\n",n);
}
/*
A Not allowed system call: runid:292141 :使用了系统禁止的操作系统调用，看看是否越权访问了文件或进程等资源
buffer overflow detected:缓冲区溢出，检查是否有字符串长度超出数组的情况*/

#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
int main()
{
    string a,b;
    cin>>a>>b;
    int res=0;
    for(int i=0;i<a.length()-b.length()+1;i++)
    {
        if(b == a.substr(i, b.length()))
        {
            res++;
        }
    }
    cout<<res<<endl;
    return 0;
}

#include "stdafx.h"
#include "string.h"

int main(int argc, char* argv[])
{
char strA[80],strB[80];
int count = 0;

scanf("%s", &strA);

scanf("%s", &strB);
char *p;
p = strstr(strA, strB);
while (p)
{
   count++;
   p++;
   p = strstr(p, strB);
}
printf("%d/n", count);
return 0;
}/*Segmentation fault:段错误，检查是否有数组越界，指针异常，访问到不应该访问的内存区域*/

//
string A("ababa");
string B("aba");
string::size_type pos = 0;
 int cnt = 0;
while ((pos = A.find_first_of(B, pos)) != string::npos)
{
    ++cnt;
    ++pos;
}