Method for segregation 0 and 1 given input array
void segregate0and1 ( int arr [ ] , int n ) { int type0 = 0 ; int type1 = n - 1 ; while ( type0 < type1 ) { if ( arr [ type0 ] == 1 ) { swap ( arr [ type0 ] , arr [ type1 ] ) ; type1 -- ; } else { type0 ++ ; } } }