Given an array of integers, return indices of the two numbers such that they add up to a specific target.
You may assume that each input would have exactly one solution, and you may not use the same element twice.
Example:
Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1]
思路：兩個數整數相加等于targe，且數組中都為大于零，故需要查找targe-x的位置
解法：
public int[] twoSum(int[] nums, int target) {
int[] result = new int[2];
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
for (int i = 0; i < nums.length; i++) {
int temp = nums[i];
if (map.containsKey(temp)) {
result[0] = map.get(temp);
result[1] = i;
return result;
}
//如果沒有，就put到map里面
else {
map.put(target - nums[i], i);
}
}
throw new IllegalArgumentException("No two sum solution");
}
