fix Pair::compareTo

NASU41 · NASU41 · commit d5af2ab6a0cd · 2021-05-22T14:08:23.000+09:00
diff --git a/Pair/Pair.java b/Pair/Pair.java
@@ -13,8 +13,9 @@ public boolean equals(Object another){
         return this.first.equals(otherPair.first) && this.second.equals(otherPair.second);
     }
     public int compareTo(Pair<S,T> another){
-        if(this.second.compareTo(another.second) == 0) return this.first.compareTo(another.first);
-        else return this.second.compareTo(another.second);
+        Comparator<Pair<S,T>> comp1 = Comparator.comparing(Pair::getFirst);
+        Comparator<Pair<S,T>> comp2 = comp1.thenComparing(Pair::getSecond);
+        return comp2.compare(this, another);
     }
     public int hashCode(){
         return first.hashCode() * 10007 + second.hashCode();

Original file line number	Diff line number	Diff line change
`@@ -13,8 +13,9 @@ public boolean equals(Object another){`
`13`	`13`	`return this.first.equals(otherPair.first) && this.second.equals(otherPair.second);`
`14`	`14`	`}`
`15`	`15`	`public int compareTo(Pair<S,T> another){`
`16`		`- if(this.second.compareTo(another.second) == 0) return this.first.compareTo(another.first);`
`17`		`- else return this.second.compareTo(another.second);`
	`16`	`+ Comparator<Pair<S,T>> comp1 = Comparator.comparing(Pair::getFirst);`
	`17`	`+ Comparator<Pair<S,T>> comp2 = comp1.thenComparing(Pair::getSecond);`
	`18`	`+ return comp2.compare(this, another);`
`18`	`19`	`}`
`19`	`20`	`public int hashCode(){`
`20`	`21`	`return first.hashCode() * 10007 + second.hashCode();`