Fibnacci string

Fibnacci string

Time Limit: 1000ms, Special Time Limit:2500ms, Memory Limit:65536KB

Total submit users: 208, Accepted users: 172

Problem 10805 : No special judgement

Problem description

The Fibnacci string is as follows:
S₁=b
S₂=a
S_k=S_k-1S_k-2 k>2
We are given a string, is there a Fibnacci string? 

Input

The input will consist of a series of string, one string per line, followed by a line containing only the char ‘0’ that signals the end of the input file and need not to be processed.
You may assume that the length of each string is no more than 1,000,000.

Output

For each string you should output the ‘true’ if the string is a Fibnacci string, or ‘false’ if the string is not a Fibnacci string and with one line of output for each line in input. 

Sample Input

abaab
abaababa
abaababaababa
0

Sample Output

true
true
false

Problem Source

HNU Contest 

 

#include<stdio.h>
#include<string.h>

char a[1000001],b[1000001],c[1000001],s[1000001];

int main()
{
    int len,len1;
    while(gets(s)&&strcmp(s,"0")!=0)
    {
        len=strlen(s);
        strcpy(a,"b");
        strcpy(b,"a");
        len1=0;
        if(strcmp(s,b)==0||strcmp(s,a)==0)   printf("true\n");
        else
        {
        for(;len>len1;)
        {
            strcpy(c,b);
            strcat(b,a);        
            strcpy(a,c);
            len1=strlen(b);
        }
        if(strcmp(s,b)==0)   printf("true\n");
        else printf("false\n");
        }
    }
   return 0;
}