multiplexer arduino code

int write_pins[] = { 0,1,2,3,4,5,6 };
long max_min_array[16][2];


int max_min(int pin,int value){
  //-------------------------------------------
  // set to initial reads and then move min_max
  // if value > min
  // if value < max
  //-------------------------------------------
  //Serial.println("inside max_min");
  //Serial.println(pin);
  int MIN = max_min_array[pin][0];
  int MAX = max_min_array[pin][1];

  if ( ( MIN && MAX ) == 0 ){
    max_min_array[pin][0] = value;
    max_min_array[pin][1] = value;
  return 0;
  }
  // min
  if ( MIN > value ){
    max_min_array[pin][0] = value;
    return 1;
  }
  // max
  if ( MAX < value ){
    max_min_array[pin][1] = value;
    return 2;
  }
  return 3;
}

int mux_pin_select(int mux_pin){
  //-------------------------------------------
  //Serial.println("inside mux_pin_select");
  // sets select pins based on pin (pin = decimal)
  // write_pins 0,1 = empty
  // write_pins 2 = Disable
  // write_pins 3,4,5,6 = S0,S1,S2,S3
  //-------------------------------------------
  int select_pin_map[] = { 3,4,5,6 };
  //Serial.println(mux_pin);
  for ( int b = 0; b < 4;b++){

    int bitset = bitRead(mux_pin, b);
    //Serial.print(bitset);
    digitalWrite(select_pin_map[b], bitset);
  }
  //Serial.println("");
  return 0;
}

int multiplex_read(){
  //-------------------------------------------
  // For mux_pin select pin "mux_pin_select()", read A0, and
  // store "max_min(mux_pin,sensorValue)"
  //-------------------------------------------
  //Serial.println("inside multiplex read");
  //Serial.println("##### select pins #####");
  for (int mux_pin = 0; mux_pin <= 15; mux_pin++){
    mux_pin_select(mux_pin);
    long sensorValue = analogRead(A0);
    for (int i = 0; i < 5; i++){
      sensorValue = analogRead(A0) + sensorValue;
    }
    sensorValue = sensorValue/5;
    int result = max_min(mux_pin,sensorValue);
/*
    Serial.print("sensorValue: ");
    Serial.print(sensorValue);
    Serial.print(" max_min_return: ");
    Serial.print(result);
    if (result == 0){
      Serial.println(" Initial Value Added");
    }
    if (result == 1){
      Serial.println(" Minimum Value Added");
    }
    if (result == 2){
      Serial.println(" Maximum Value Added");
    }
    if (result == 3){
      Serial.println(" No Value Added");
    }
*/
  }
  return 0;
}


void setup(){
  // clear max_min_array and multiplex_read_array
  for ( int i = 0; i <= 15; i++){
    max_min_array[i][0] = 0;
    max_min_array[i][1] = 0;
  }
  // initialize write pins
  for ( int i = 0; i <= 7; i++){
    pinMode(write_pins[i], OUTPUT);
  }
  Serial.begin(115200);
  Serial.println("\nInitializing Serial.\nInput Alphanumeric and Press Enter/Send.");
}

void loop(){
  if ( Serial.available()){
    Serial.println("\nStarting multiplex_read().");
    while (true){
      for ( int i = 0; i <= 250; i++){  // approx 4 seconds with the current code
        multiplex_read();
      }
      Serial.println("### Min Max Array #########");
      for (int i = 0; i <= 15; i++){
        Serial.print("\n### Row/Mux: ");
        Serial.println(i);
        for (int j = 0; j <= 1; j++){
        Serial.print(max_min_array[i][j]);
        Serial.print(" ");
        }
      }
    }
  }
}


##################
output
###################

### Min Max Array #########

### Row: 0
365 375
### Row: 1
441 458
### Row: 2
231 248
### Row: 3
420 432
### Row: 4
335 369
### Row: 5
0 0
### Row: 6
0 0
### Row: 7
0 0
### Row: 8
0 0
### Row: 9
0 0
### Row: 10
0 0
### Row: 11
0 0
### Row: 12
0 0
### Row: 13
0 0
### Row: 14
0 0
### Row: 15
0 0 ### Min Max Array #########

### Row: 0
365 1096
### Row: 1
441 460
### Row: 2
231 260
### Row: 3
418 432
### Row: 4
335 376
### Row: 5
0 0
### Row: 6
0 0
### Row: 7
0 0
### Row: 8
0 0
### Row: 9
0 0
### Row: 10
0 0
### Row: 11
0 0
### Row: 12
0 0
### Row: 13
0 0
### Row: 14
0 0
### Row: 15
0 0 ### Min Max Array #########

### Row: 0
290 1096
### Row: 1
194 1078
### Row: 2
231 272
### Row: 3
409 432
### Row: 4
335 376
### Row: 5
0 0
### Row: 6
0 0
### Row: 7
0 0
### Row: 8
0 0
### Row: 9
0 0
### Row: 10
0 0
### Row: 11
0 0
### Row: 12
0 0
### Row: 13
0 0
### Row: 14
0 0
### Row: 15
0 0 ### Min Max Array #########

### Row: 0
290 1096
### Row: 1
194 1078
### Row: 2
231 1043
### Row: 3
406 432
### Row: 4
335 379
### Row: 5
0 0
### Row: 6
0 0
### Row: 7
0 0
### Row: 8
0 0
### Row: 9
0 0
### Row: 10
0 0
### Row: 11
0 0
### Row: 12
0 0
### Row: 13
0 0
### Row: 14
0 0
### Row: 15
0 0 ### Min Max Array #########

### Row: 0
290 1096
### Row: 1
194 1078
### Row: 2
109 1043
### Row: 3
356 1020
### Row: 4
335 379
### Row: 5
0 0
### Row: 6
0 0
### Row: 7
0 0
### Row: 8
0 0
### Row: 9
0 0
### Row: 10
0 0
### Row: 11
0 0
### Row: 12
0 0
### Row: 13
0 0
### Row: 14
0 0
### Row: 15
0 0 ### Min Max Array #########

### Row: 0
290 1096
### Row: 1
194 1078
### Row: 2
109 1043
### Row: 3
317 1020
### Row: 4
286 1068
### Row: 5
0 0
### Row: 6
0 0
### Row: 7
0 0
### Row: 8
0 0
### Row: 9
0 0
### Row: 10
0 0
### Row: 11
0 0
### Row: 12
0 0
### Row: 13
0 0
### Row: 14
0 0