基础算法一

字符串匹配

//字符串匹配
#include<iostream>
#include<windowsx.h>
#include<string.h>
using namespace std;

int ViolentMatch(char *s, char *t)
{
    int slen = strlen(s);
    int tlen = strlen(t);
    int i = 0,j = 0;
    while (i < slen && j< tlen)
    {
        if (s[i] == t[j])
        {
            i++;
            j++;
        }
        else
        {
            i = i - j + 1;
            j = 0;
        }
    }
    if (j == tlen)
    {
        return i - j;
    }
    else
    {
        return -1; 
    }

}

int  main()
{
    //char *a="aaaabaa" ; char *b="b" ;
    string a;string b;
    

    cout << ViolentMatch(a, b) << endl;
    system("pause");
    return 0;

最大回文子串

//最大回文子串
/*
#include<iostream>

using namespace std;

int LongestPalinderom(char *s, int n)
{
    int i, j, max, c;
    if (s == 0 || n < 0)
    {
        return 0;
    }
    max = 0;
    for (i = 0;i < n;++i)
    {
        for (j = 0;(i - j >= 0) && (i + j < n);++j)
        {
            if (s[i - j] != s[i + j])
            {
                break;
            }
            c = j * 2 + 1;//对称字符串为奇数
        }
        if (c > max)
        {
            max = c;
        }
        for (j = 0;(i - j >= 0) && (i + j + 1 < n);++j)
        {
            if (s[i - j] != s[i + j + 1])
            {
                break;
            }
            c = j * 2 + 2;//对称字符串为偶数
        }
        if (c > max)
        {
            max = c;
        }
    }
    return max;
}

int main()
{
    char a[64];
    int n;
    cin >> a;
    n=strlen(a);
    cout << LongestPalinderom(a, n) << endl;
    system("pause");
    return 0;    
}

*/

全排列

//全排列
/*
#include<iostream>  
using namespace std;
#include<assert.h>  

//在[nBegin,nEnd)区间中是否有字符与下标为pEnd的字符相等  
bool IsSwap(char* pBegin, char* pEnd)
{
    char *p;
    for (p = pBegin; p < pEnd; p++)
    {
        if (*p == *pEnd)
            return false;
    }
    return true;
}
void Permutation(char* pStr, char *pBegin)
{
    assert(pStr);

    if (*pBegin == '')
    {
        static int num = 1;  //局部静态变量，用来统计全排列的个数  
        printf("第%d个排列	%s
", num++, pStr);
    }
    else
    {
        for (char *pCh = pBegin; *pCh != ''; pCh++)   //第pBegin个数分别与它后面的数字交换就能得到新的排列     
        {
            if (IsSwap(pBegin, pCh))
            {
                swap(*pBegin, *pCh);
                Permutation(pStr, pBegin + 1);
                swap(*pBegin, *pCh);
            }
        }
    }
}

int main(void)
{
    char str[64];
    //    int n;
    cin >> str;
    //    n=strlen(a)-1; 
    // char str[] = "baa";  
    Permutation(str, str);
    system("pause");
    return 0;
}

*/

汉诺塔

//汉诺塔

#include<iostream>

using namespace std;

void hanoi(int n, char one, char two, char three)//n个盘子从one移到three（借助two)
{
    int count = 0;
    void move(char x, char y);
    if (n == 1)
        move(one, three);
    else
    {
        hanoi(n - 1, one, three, two);//n-1个盘子从one移到two
        move(one, three);
        hanoi(n - 1, two, one, three);//n-1个盘子在从two移到three
    }
}

void move(char x, char y)
{
    cout << x << "-->" << y << endl;
}

int main()
{
    void hanoi(int n, char one, char two, char three);
    int m;      //输入多少个盘子
    cin >> m;
    hanoi(m, 'A', 'B', 'C');
    system("pause");
    return 0;
}

 

反转I am a boy 为boy a am I 

//反转I am a boy 为boy a am I 
/*
#include<iostream>
#include <string.h>
#include <cstdio>
using namespace std;

void RS(char*bp, char *ep)
{
    while (bp<ep)
    {
        //char temp = *bp;
        //*bp = *ep;
        //*ep = temp;
        
        swap(*ep, *bp);
        bp++;
        ep--;
    }
}
char *Reverse(char *s)
{
    int len = strlen(s);
    char *es = s + len - 1;
    RS(s, es);

    char *p1 = s;
    char *p2 = s;
    while (*p2 != '')
    {
        while (*p2 != '' && *p2 != ' ')
        {
            p2++;
        }

        RS(p1, p2 - 1);
        if (*p2 == ' '&& *p2 != '')
        {
            p2++;
            p1 = p2;
        }
    }
    return s;
}
int main()
{
    char str[500];
    //getchar();
    gets_s(str);
    cout << Reverse(str) << endl;
    system("pause");
    return 0;
}
*/