March 31, 2013

• 呢個post, 係用黎恥笑自己submit左個order n^5既code
  過large judge timeout

  連寫呢D唔洗algorithm既code都搞左咁耐-.-
  唔stackoverflow下真係唔知有D咁既方法compare兩條ArrayList係咪一樣
  聽日再諗過個醒少少既algorithm

  sum of 3 numbers

  http://leetcode.com/onlinejudge#question_15

  public ArrayList<ArrayList<Integer>> threeSum(int[] num) {
   ArrayList<ArrayList<Integer>> result = new ArrayList<ArrayList<Integer>>();  
   Arrays.sort(num);
   for (int i = 0; i < num.length; i++){
    for (int j = i+1; j < num.length; j++){
     for (int k = j+1; k < num.length; k++){
      if ((num[i] + num[j] + num[k]) == 0){
       ArrayList<Integer> list = new ArrayList<Integer>();
       list.add(num[i]); list.add(num[j]); list.add(num[k]);
       Boolean repeated = false;
       for (int m = 0; m < result.size(); m++){
        List<Integer> added = new ArrayList<Integer>(result.get(m));
        added.removeAll(list);
        if (added.size () == 0) repeated = true;
       }
       if (!repeated) result.add(list);
      }
     }
    }
   }
   return result;
  }

  • 12:26 pm
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