feat: update structure

cs2030s/labs/PE2/plab0124/Pair.java

@@ -0,0 +1,43 @@
+/**
+ * CS2030S PE2 
+ * AY2022/23 Semester 2.
+ * 
+ * @author A0253252M
+ **/
+class Pair<T,S> {
+  private T fst;
+  private S snd;
+  public Pair(T fst, S snd) {
+    this.fst = fst;
+    this.snd = snd;
+  }
+  public T getFst() {
+    return this.fst;
+  }
+  public S getSnd() {
+    return this.snd;
+  }
+  public void setFst(T fst) {
+    this.fst = fst;
+  }
+  public void setSnd(S snd) {
+    this.snd = snd;
+  }
+  @Override
+  public String toString() {
+    return "(" + this.fst + ", " + this.snd + ")";
+  }
+  
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj) {
+      return true;
+    }
+    if(!(obj instanceof Pair<?,?>)) {
+      return false;
+    }
+    Pair<?,?> pr = (Pair<?,?>) obj;
+    return this.fst.equals(pr.fst) &&
+           this.snd.equals(pr.snd);
+  }
+}