CareerCup

public int convertStringToInt(String num){
		int result=0;
		int zeroAscii=48;
		int nineAscii=57;
		for(char c: num.toCharArray()){
			if(c>=zeroAscii && c<=nineAscii){
				result=result*10+(c-zeroAscii);
			}else
				return -1;
		}
		return result;
	}

<pre lang="c" line="1" title="CodeMonkey33935" class="run-this">#include <stdio.h>
#include <string.h>

int main()
{
char *s = "12345";
char *p;
int sum = 0;

for(p = s; *p!='\0';p++)
sum = sum*10 + ((int)*p-'0');
printf("%d\n", sum);

return 0;
}


</pre><pre title="CodeMonkey33935" input="yes">
</pre>

//C++ COde
int zeroAscii = 48;
int value = 0;
string str = "98989";
int len = strlen(str);
for (int i=0;str!=NULL;++str,++i)
  i += ((int)(str[0])-zeroAscii)*pow(10,len-i);

The fastest way to get number of a given string:
int number = 98989;

int string_to_positive_int(char *szN)
{
int nTotal = 0;

while (*szN)
{
nTotal = *szN++ - '0' + nTotal << 1 + nTotal << 3;
}

return nTotal;
}

char* str;
int tot = 0;

for(char* i = str; i != NULL; i++)
   tot = 10*tot+i-'0';

Here is the solution...

public static void main(String args[]){
		
		String numStr = "123456";
		
//		1*100000 (10^5)= 100000
//		2*10000 (10^4) =  20000
//		3*1000 (10^3)  =   3000
//		4*100 (10^2)   =    400
//		5*10 (10^1)    =     50
//		6*1 (10^0)     =      6
//		------------------------
//		                 123456
//		------------------------
		
		int length = numStr.length();
		char[] charArr = numStr.toCharArray();
		int total = 0;
		int index=length-1;
		for(int i=0;i<length;i++){
			total = (int) (total + (charArr[index]-48)*Math.pow(10, i));
			index--;
		}
		
		System.out.println(total);
	}

Guys simple code O (n) complexity:-

public static int str_to_num(String str)
	{ 
	  int i =0 ; 	
	  int num = 0 ; 
	  int n = str.length()-1;
	  while(i<=n)
	  {
	   num = num*10 + ((int)str.charAt(i)- 48);
	   i++ ;
	  }
	  
	  return num ;

}

int chartoi(char *str)
{
int n=0;
for( ; *str; str++)
n = n*10 + (*str - 48);
return n;
}

public class ConvertStringToNumber{

public static int convertToNum(String numStr){
Char ch[ ] = numStr.toCharArray();
int sum = 0;
into zeroAsValue = (int) '0';
for(char c : ch){
into tempZeroAsValue = (int) c;
sum = (sum*10) + (tempZeroAsValue - zeroAsValue);
}

system.out.println("convertedValueIs===>" +sum);
retun sum;
}
public static void main(String arg[ ] ){
String convertString = "98989"

convertToNum(convertString);
}
}

I had a few interviews with financial companies and they mostly ask stupid questions like this. Few of them actually ask questions on syntactical errors and code based errors and evaluate a candidate's skills. It's stupid to evaluate someone's skills on that basis. I guess thats the reason we have so many stupid financial institutions n even though they rob people of their money their software sux bawls.