Here we need to check processed [ 1 ] only for 2 since 0 is less than 1 and we can replace it anytime
if ( s [ i ] == '1' && count [ 1 ] > reqd ) { if ( count [ 0 ] < reqd ) { s [ i ] = '0' ; count [ 0 ] ++ ; count [ 1 ] -- ; } else if ( count [ 2 ] < reqd && processed [ 1 ] >= reqd ) { s [ i ] = '2' ; count [ 2 ] ++ ; count [ 1 ] -- ; } }