基本算法实现（C）

模式串匹配算法：

#include "stdio.h"
int Index(char *S,char *T,int pos)
{
    int i,j,slen,tlen;
    slen=strlen(S);
    tlen=strlen(T);
    i=pos;
    j=0;
    while(i<slen&&j<tlen)
    {
        if(S[i]==T[j])
        {
            i++;
            j++;
        }
        else
        {
            i=i-j+1;//如果j=0就相当于将i右移一位
            j=0;
        }
    }
    if(j>=tlen)
        return i-tlen;
    else
        return -1;
}
void main()
{
    int i=0;
     char s[]="assacashhhghkjklklklljlhghfgfdfsdshjhjjjjjjjjjjjjghfgfgdfdfdsdsadghyyy6577777756fgdssd";
     char p[]="hhhgh";
    i=Index(s,p,1);
    printf("i=%d\n",i);
}

#include "stdio.h"
void Get_next(char *p,int next[])
{
    int i,j,slen;
    slen=strlen(p);
    i=0;
    next[0]=-1;
    //next[1]=0;
    j=-1;
    while(i<slen)
    {
        if(j==-1||p[i]==p[j])
        {
            i++;
            j++;
            next[i]=j;
        }
        else j=next[j];
    }
}
int Index_KMP(char *s,char *p,int pos,int next[])
{
    int i,j,slen,plen;
    i=pos-1;
    j=-1;
    slen=strlen(s);
    plen=strlen(p);
    while(i<slen&&j<plen)
    {
        if(j==-1||s[i]==p[j])
        {
            i++;
            j++;
        }
        else j=next[j];
    }
    if(j>=plen) return i-plen;
    else return -1;
}
void main()
{
    char s[]="assacashhhghkjklklklljlhghfgfdfsdshjhjjjjjjjjjjjjklkloiiuui9   igghfgfgdfdfdsdsadghyyy6577777756fgdssd";
    char p[]="jjjjjjjklkloiiuui9   igghfgfgdf";
    int next[100];
    Get_next(p,next);
    printf("%d\n",Index_KMP(s,p,0,next));


}

LCS（最长公共字串）：

#include "stdio.h"
void LCS(char s1[],char s2[])
{
    int i,j,begin=0,l1,l2,maxlen=0,*matrix;
    l1=strlen(s1);
    l2=strlen(s2);
    matrix=(int *)malloc(l1*sizeof(int));
    //for(i=0; i<l1; i++)matrix[i]=0;
    for(i=0; i<l2; i++)
        for(j=l1-1; j>=0; --j)
        {
            if(s2[i]==s1[j])
            {
                if((j==0)||(i==0))
                    matrix[j]=1;
                else
                    matrix[j]=matrix[j-1]+1;
            }
            else
                matrix[j]=0;
            if(matrix[j]>maxlen)
            {
                maxlen=matrix[j];
                begin=j;
            }
        }
    if(maxlen==0)
        printf("没有公共子串");
    else
    {
        printf("公共子串长度：%d\n",maxlen);
        printf("begin=%d\n",begin);
        for(i=begin-maxlen+1; i<=begin; i++)
            printf("%c",s1[i]);
    }
    free(matrix);
}
void main()
{
    char s1[]="assacashhhghkjklklklljlhghfgfdfsdshjhjjjjjjjjjjjjghfgfgdfdfdsdsadghyyy6577777756fgdssd";
    char s2[]="hhhgh";
    LCS(s1,s2);
}

汉诺塔实现：

/* Note:Your choice is C IDE */
#include "stdio.h"
void main()
{
    void hanoi(int n,char a,char b,char c);
    hanoi(34,'A','B','C');  
}
void hanoi(int n,char a,char b,char c)
{
    if(n==1)printf("%c=>%c\n",a,c);
    else
    {
        hanoi(n-1,a,c,b);
        printf("%c=>%c\n",a,c);
        hanoi(n-1,b,a,c);
    }
}