4Sum
来源:互联网 发布:中国网络移动经纪人 编辑:程序博客网 时间:2024/06/06 18:29
会了3Sum,4Sum应该就是多来一笔了。
/**
* @param numbers : Give an array numbersbers of n integer
* @param target : you need to find four elements that's sum of target
* @return : Find all unique quadruplets in the array which gives the sum of
* zero.
*/
public ArrayList<ArrayList<Integer>> fourSum(int[] numbers, int target) {
/* your code */
ArrayList<ArrayList<Integer>> results = new ArrayList<>();
if (numbers == null || numbers.length < 4) {
return results;
}
Arrays.sort(numbers);
for (int i = 0; i < numbers.length - 3; i++) {
if (i > 0 && numbers[i] == numbers[i - 1]) {
continue;
}
for (int j = i + 1; j < numbers.length - 2; j++) {
if (j > i + 1 && numbers[j] == numbers[j - 1]) {
continue;
}
int left = j + 1;
int right = numbers.length - 1;
while (left < right) {
int sum = numbers[i] + numbers[j] + numbers[left] + numbers[right];
if (sum == target) {
ArrayList<Integer> list = new ArrayList<>();
list.add(numbers[i]);
list.add(numbers[j]);
list.add(numbers[left]);
list.add(numbers[right]);
results.add(list);
left++;
right--;
while (left < right && numbers[left] == numbers[left - 1]) {
left++;
}
while (left < right && numbers[right] == numbers[right + 1]) {
right--;
}
} else if (sum < target) {
left++;
} else {
right--;
}
}
}
}
return results;
}
- 【Leetcode】4Sum (Sum)
- leetcode 2 sum 3sum 4sum
- 3Sum 3Sum Closest 4Sum
- 3Sum & 3Sum Closest & 4Sum
- 2Sum 3Sum 4Sum
- 3sum、3Sum closet、 4sum
- 3Sum, 3Sum Closest, 4 Sum
- Leetcode 2SUM-3SUM-4SUM
- Leetcode-2sum,3sum,4sum
- leetcode 2 sum & 3 sum & 4 sum
- 4Sum
- 4Sum
- 4Sum
- 4Sum
- 4Sum
- 4Sum
- 4Sum
- 4Sum
- XSS跨站攻击详解
- 人脸识别:PairLoss
- Linux下的TCP/IP编程----UDP实践篇
- Installing optional Nginx modules with apt-get nginx_uploadprogress_module
- 使用环信SDK开发免费语音通话app原型测试成功
- 4Sum
- MySQL的参照完整性(多表的设计):定义外键
- OpenCV3.0 源码方式安装
- Vim插件管理:Pathogen安装
- IOS App 的图标和启动图的烦恼
- 多态程序
- leetcode_138 Copy List with Random Pointer
- Dropout 与 DropConnect
- www