串定位运算（完整程序）

在一个字符串中定位子字符串的位置。

#include<stdio.h>#include<string.h>#include<assert.h>int locate(const char *mainString,const char *childString){    int i,j,k;    int m = strlen(mainString);    int n = strlen(childString);    for(i = 0;i<=m - n;i++)    {        j = 0; k = i;        while(j<n&&(mainString[k]==childString[j])){            j++;k++;        }        if(j==n)        {            printf("succeed!\n");            return i;        }    }    return -1;}void main(){    int l;    char *mainStr,*childStr;    mainStr = "abcdefg";    childStr = "def";    l = locate(mainStr,childStr);    if(l==-1)    {        printf("not succeed!\n");    }    else{    printf("位置是%d\n",l);}}