2014
02-14

Parity

A bit string has odd parity if the number of 1′s is odd. A bit string has even parity if the number of 1′s is even.Zero is considered to be an even number, so a bit string with no 1′s has even parity. Note that the number of
0′s does not affect the parity of a bit string.

The input consists of one or more strings, each on a line by itself, followed by a line containing only "#" that signals the end of the input. Each string contains 1�31 bits followed by either a lowercase letter ‘e’ or a lowercase letter ‘o’.

The input consists of one or more strings, each on a line by itself, followed by a line containing only "#" that signals the end of the input. Each string contains 1�31 bits followed by either a lowercase letter ‘e’ or a lowercase letter ‘o’.

101e
010010o
1e
000e
110100101o
#

1010
0100101
11
0000
1101001010

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

char str[110] ;

int main ()
{
int i, cnt, len ;

while (gets (str))
{
if (strcmp(str, "#") == 0) break ;
len = strlen(str) ;
for(i = 0, cnt = 0 ; i < len-1 ; i++)
if (str[i] == '1') cnt++ ;
if ((cnt%2 == 0 && str[len-1] == 'o') ||
(cnt%2 == 1 && str[len-1] == 'e'))
str[len-1] = '1' ;
else str[len-1] = '0' ;
puts (str) ;
}
return 0 ;
}

1. #!/usr/bin/env python
def cou(n):
arr =
i = 1
while(i<n):
arr.append(arr[i-1]+selfcount(i))
i+=1
return arr[n-1]

def selfcount(n):
count = 0
while(n):
if n%10 == 1:
count += 1
n /= 10
return count