KMP算法2

            给定一个主串s，一个子串sub，将主串中的所有子串替换成replaceStr，并将最终结果输出来。

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int next[20];
void getNext(char pattern[])
{
    int k=-1,len=strlen(pattern),j=0;
    next[0]=-1;
    while(j<len){
        if(k==-1||pattern[k]==pattern[j]){
            k++;j++;
            next[j]=k;
        }else{
            k=next[k];
        }
    }
}

int KMP(char text[],char pattern[])
{
    int i=0,j=0,lent=strlen(text),lenp=strlen(pattern);
    getNext(pattern);
    while(i<lent&&j<lenp){
        if(j==-1||text[i]==pattern[j]){
            i++;j++;
        }else{
            j=next[j];
        }
    }
    if(j==lenp)
        return i-j;
    return -1;
}

char* strSub(char* s,int pos,int length)//字符串截取函数
{
    char *sub=(char *)calloc(length,sizeof(char));
    int i=pos;
    int count=0;
    while(count<length)
    {
        sub[count]=s[i];
        i++;
        count++;
    }
    sub[count]='\0';
    return sub;
}

char* strReplace(char* s,char* sub,char* replaceStr)//字符串替换函数
{
    int end;
    char* temp1;
    char* temp2;
    int begin=0;
    int subLength=strlen(sub);
    end=KMP(s,sub);
    while(end!=-1)
    {
        temp1=strSub(s,begin,end-begin);
        temp2=strSub(s,end+subLength,strlen(s)-(end+subLength));
        s=strcat(temp1,replaceStr);
        s=strcat(s,temp2);
        end=KMP(s,sub);
    }
    return s;
}
int main()
{
    char s[100],sub[10],replaceStr[10];
    char *answer=(char *)calloc(100,sizeof(char));
    printf("input s:\n");
    gets(s);
    printf("input sub:\n");
    gets(sub);
    printf("input replaceStr:\n");
    gets(replaceStr);
    answer=strReplace(s,sub,replaceStr);
    printf("final str is:\n");
    puts(answer);
    return 0;
}