15. 3Sum

Author: RootHex200

problem46/main.dart

@@ -0,0 +1,48 @@
+
+
+//15. 3Sum
+
+void main(List<String> args) {
+  print(threeSum([-1,0,1,2,-1,-4]));
+  print(threeSum([0,1,1]));
+  print(threeSum([-2,0,0,2,2]));
+}
+ threeSum(List<int> list){
+  list.sort();
+  var resultList=[];
+  for(int i=0;i<list.length-2;i++){
+    
+    var left=i+1;
+    var right=list.length-1;
+    if(i > 0 && list[i] == list[i-1]){
+      continue;
+    }
+          
+    while(left<right){
+      int sum=list[i]+list[left]+list[right];
+      if(sum>0){
+        right --;
+      }
+      if(sum<0){
+        left++;
+      }
+      if(sum==0){
+        var temp=[];
+        temp.add(list[i]);
+        temp.add(list[left]);
+        temp.add(list[right]);
+        resultList.add(temp);
+        left ++;
+        right --;
+        while(left<list.length&& list[left]==list[left-1]){
+          left++;
+        }
+        while(right>i &&list[right]==list[right+1]){
+          right --;
+        }
+      }
+    }
+  }
+
+  return resultList;
+}