文章目录
没什么好说的，这就是三数之和的变种。
- 先排序
- 再确定一个数，用双指针移动两个数，比较diff和当前diff值即可。
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46import java.util.Arrays;
public class ThreeSumClosest16 {
/***
* 三数之和的变种，先排序，指定一个值后，再用双指针
*
*/
public int threeSumClosest(int[] nums, int target) {
int result = nums[0] + nums[1] + nums[2];
int diff = Math.abs(result - target);
// 先排序
Arrays.sort(nums);
int left, right;
for (int i = 0; i < nums.length - 2; i++) {
int current = nums[i];
// 双指针，系三数之和变种
left = i + 1;
right = nums.length - 1;
while (left < right) {
int sum = current + nums[left] + nums[right];
int newDiff = Math.abs(sum - target);
if (newDiff < diff) {
diff = newDiff;
result = sum;
}
// 如果当前和比预期的target小，则右移left指针
if (sum < target)
left++;
else
// 否则左移right指针
right--;
}
}
return result;
}
public static void main(String[] args) {
ThreeSumClosest16 threeSumClosest16 = new ThreeSumClosest16();
int[] nums = {-1, 2, 1, -4};
int target = 1;
int result = threeSumClosest16.threeSumClosest(nums, target);
System.out.println(result);
}
}
