求最大遞增數

要求：求最大遞增數   如：1231123451   輸出12345    

#include<stdio.h>  
#include<assert.h>  
void find(char *s)  
{  
    int maxleng = 0;  
    int length = 1;  
    int pos = 0;  
    int i = 0;  
    while(s[i] !='\0')  
    {     
        if((s[i])<'0'||(s[i]>'9'))  
        {  
            assert(0);  
        }  
        if((s[i+1]-'0') > (s[i] -'0'))  
        {  
            length++;  
            i++;  
            continue;  
        }  
        if(length > maxleng)  
        {  
            maxleng = length;  
            pos = i -maxleng;  
            pos++;  
            length = 1;  
            i++;  
            continue;  
        }  
        i++;  
        length = 1;  
    }  
    for(int j =0; j < maxleng; j++)  
    {  
        printf("%c",s[pos++]);  
    }  
}  
int main( )  
{  
    char s[100];  
    scanf("%s",s);  
    find(s);  
    return 0;  
}