76 lines
1.5 KiB
Java
76 lines
1.5 KiB
Java
/*
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store variable names with stored value
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*/
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import java.util.ArrayList;
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public class MemTable {
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private ArrayList<String> names;
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private ArrayList<Double> values;
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public MemTable() {
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names = new ArrayList<String>();
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values = new ArrayList<Double>();
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}
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public String toString() {
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String s = "----\n";
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for( int k=0; k<names.size(); k++ ) {
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s += names.get(k) + " " + values.get(k) + "\n";
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}
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return s;
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}
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public int size() {
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return names.size();
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}
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// store value for name, adding name if not already
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// there
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public void store( String name, double value ) {
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int loc = findName( name );
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if ( loc < 0 ) {// add new pair
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names.add( name );
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values.add( value );
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}
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else {// change value for existing pair
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values.set( loc, value );
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}
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}// store
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// retrieve value for given name
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public double retrieve( String name ) {
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int loc = findName( name );
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if ( loc >= 0 ) {// add new pair
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return values.get( loc );
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}
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else {
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System.out.println("variable [" + name + "] not found");
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System.exit(1);
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return 0;
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}
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}// retrieve
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// return index of name in names, or -1 if
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// not found
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private int findName( String name ) {
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// locate name
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int loc = -1;
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for (int k=0; k<names.size() && loc<0; k++) {
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if ( names.get(k).equals(name) ) {
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loc = k;
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}
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}
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return loc;
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}// findName
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}
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