atoi.c(문자열을 숫자로 출력)

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

int my_atoi(char *str) {
	int num = 0;
	int len = strlen(str);
	for (int i = len-1; i>=0; i--){
		num += (str[len-1-i] - '0')*(pow(10,i));
	}
	return num; 
}

int main(void){
	int i = my_atoi("100");
	printf("i : %d\n",i);
	return 0;
}