NVIDIA interview question

How would you implement int atoi ( const char * str );

Interview Answers

Anonymous

21 Aug 2011

I parsed the string from left to right, multiplying the temp int by 10 for each char traversed.

Anonymous

10 Jan 2012

You need to subtract the ascii value of zero to get the integer value of the char before multiplying by 10.

Anonymous

19 May 2012

#include #include unsigned int my_atoi(const char* str) { int num = 0; while (*str) { num *= 10; num += (*str++ - '0'); } return num; } int main(int argc, char* argv[]) { printf("atoi(%s)=%d\n",argv[1], my_atoi(argv[1]) ); return 0; }