I am attempting to sort the values of various "pc specs" based on a function and output the first and second best pc scores based on the function:
score[i] = 2*pcram[i] + 3*pccpu[i] + pchdd[i];
The sorting is here:
//place sorted data into seperate arrays to make calculations more logical to look at
for (i = 0; i < numpc; i++){
pcram[i] = Integer.parseInt(pcname[i][1]);
pccpu[i] = Integer.parseInt(pcname[i][2]);
pchdd[i] = Integer.parseInt(pcname[i][3]);
}
//solve the score and find first and second place
for (i = 0; i < numpc; i++){
score[i] = 2*pcram[i] + 3*pccpu[i] + pchdd[i];
}
for (i = 0; i < numpc - 1; i++){
if (i == 0 && score[i + 1] > score[i]){
first = i + 1;
second = i;
}
if(i == 0 && score[i + 1] > score[i]){
first = i;
second = i+1;
}
if (score[i + 1] > score[i]){
second = first;
first = i+1;
}
if (score[i] > score[i+1]){
second = first;
first = i;
}
}
System.out.println(pcname[first][0] + " " + score[first]);
System.out.println(pcname[second][0] + " " + score[second] + " " + score[0]);
A sample input that causes an error is:
(The input is as follows: number of PCs, Name of PC, RAM, CPU, HDD)
4
Apple 16 3 500
Dell 16 2 500
HP 8 2 500
Custom 1000 1000 1000
Obviously, the program outputs Custom as first but then goes to say that Dell is second. I have attempted to cover all scenarios with no avail. Thanks in advance.
Edit : As requested, the full program. (This implements a suggested sorting method, the original is posted above)
public static void main(String[] args) {
Scanner nameinput = new Scanner(System.in);
Scanner datainput = new Scanner(System.in);
int numpc = datainput.nextInt();
String[][] pcname = new String[numpc][5]; //hold sorted data
String[] pcdata = new String[numpc]; //hold unsorted data
int i = 0;
int first = 0;
int second = 0;
int[] score = new int[numpc];
int[] pcram = new int[numpc];
int[] pccpu = new int[numpc];
int[] pchdd = new int[numpc];
//begin program
for (i = 0; i < numpc; i++){
pcdata[i] = nameinput.nextLine(); //get unsorted data
}
for (i = 0; i < numpc; i++){
pcname[i] = pcdata[i].split(" "); //sort data
}
//place sorted data into seperate arrays to make calculations more logical to look at
for (i = 0; i < numpc; i++){
pcram[i] = Integer.parseInt(pcname[i][1]);
pccpu[i] = Integer.parseInt(pcname[i][2]);
pchdd[i] = Integer.parseInt(pcname[i][3]);
}
//solve the score and find first and second place
for (i = 0; i < numpc; i++){
score[i] = 2*pcram[i] + 3*pccpu[i] + pchdd[i];
}
for(i = 0; i<score.length-1; i++){ //first find and store the highest values
if(score[i]> score[i+1]){
if(score[i]>first){
first = score[i];
}
if(score[i+1]>second){
second = score[i+1];
}
} else {
if(score[i+1]>first){
first = score[i+1];
}
if(score[i]>second){
second = score[i];
}
}
}
for(i= 0; i<score.length; i++){ //now get the index of that value
if(first == score[i]){
first = i;
break;
}
}
for(i= 0; i<score.length; i++){ //index for second
if(second == score[i]){
second = i;
break;
}
}
System.out.println(pcname[first][0] + " " + score[first]);
System.out.println(pcname[second][0] + " " + score[second] + " " + score[0]);
nameinput.close();
datainput.close();
}
Looks like you simply mixed up the comparator signs.
for (i = 0; i < numpc - 1; i++){
if (i == 0 && score[i + 1] > score[i]){
first = i + 1;
second = i;
}
if(i == 0 && score[i + 1] < score[i]){ //<--- you had > here
first = i;
second = i+1;
}
if (score[i + 1] > score[i]){
second = first;
first = i+1;
}
if (score[i] > score[i+1]){
second = first;
first = i;
}
}
* EDIT * I think the problem is that you don't compare if the value of i is actually greater or less than the value in first or second, you should try this one instead:
int first = 0, second = 0;
for(i = 0; i<score.length-1; i++){ //first find and store the highest values
if(score[i]> score[i+1]){
if(score[i]>first){
second = first; // *NEW* the former first place is now the second !
first = score[i]; //first = 541 //NAN // NAN
}
if(score[i+1]>second){ //second = 538 //NAN // NAN
second = score[i+1];
}
} else {
if(score[i+1]>first){
second = first;
first = score[i+1];//NAN // 522< 541 // first = 6000
}
if(score[i]>second){
second = score[i];//NAN // NAN // NAN
}
}
}
Note: The strange comments are to follow what happens in the loop. Interpret them as colums (where each column = one cycle of the loop)
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