#include<ctype.h>
 double atof(char s[]){
 double val, power;
 int i, sign;
 for( i=0; isspace(s[i]); i++) /* preskakanje belina */
 ;
 sign = ( s[i]==’-’ ) ? -1 : 1;
 if( s[i]==’+’ || s[i]==’-’ )
 i++;
 for(val=0.0; isdigit(s[i]); i++)
 val = 10.0*val + (s[i]-’0’);
 if(s[i]==’.’)
 i++; 
 for(power=1.0; isdigit(s[i]); i++){
 val = 10.0*val + (s[i]-’0’);
 power *= 10;
 }

 return sign*val/power;
 }