fibonacci_big(datalab )

#include<stdio.h>
#include<string.h>
#define M 5000
#define N 5000
char ts1[M],ts2[M],s1[M],s2[M],s3[M],t[M],s4[M],str1[M],str2[M];
struct{
char str[M];


}arr[N+5];



int main(){
int i,len1,len2 ,j,k,sum ,carry ;
int max,min,kk,jj,ii;
strcpy(str2,"0\0");
strcpy(str1,"1\0");
kk =1;
while(1){

strcpy(ts1,str1);
strcpy(ts2,str2);

len1 = strlen(ts1);
len2 = strlen(ts2);
if(len1< len2)
{
    strcpy(t,ts1);
    strcpy(ts1,ts2);
    strcpy(ts2,t);

max =  len2;
min =  len1;
}
else{
    max = len1;
    min = len2;

}

k = strlen(ts1);
for(i = 0;i< k ;i++)
{
    s1[i] = ts1[k-i-1];

}
s1[i] = '\0';
k = strlen(ts2);
for(i = 0;i< k ;i++)
{
    s2[i] = ts2[k-i-1];

}
s2[i] = '\0';


i = 0;
carry   = 0;
    for(k = 0 ; k< min; k++)
    {
        j = (s1[k]-'0') + (s2[k]-'0')+ carry ;
         sum = j%10;
         carry = j/10;
        s3[k] = sum+'0' ;

    }

        for(;k< max ;k++)
        {
        j = (s1[k]-'0') + carry ;
         sum = j%10;
         carry = j/10;
        s3[k] = sum+'0' ;

        }
        if(carry!= 0){
            while(carry != 0){
            sum = carry % 10;
            s3[k++] = sum +'0';
             carry/=10;
            }
        }




s3[k] = '\0';
k = strlen(s3);
for(i = 0;i< k ;i++)
{
    s4[i] = s3[k-i-1];

}
s4[i] = '\0';
strcpy(arr[kk++].str,s4);
strcpy(str1,str2);
strcpy(str2,s4);
ii++;
if(kk == 1000)break;
}
printf("code ready\n");

while(scanf("%d",&k)==1){


printf("%dth fib is %s\n",k,arr[k].str);
}
return 0;}