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].
Java實現:
public class Solution {
public int[] twoSum(int[] nums, int target) {
HashMap<Integer,Integer> map=new HashMap<Integer,Integer>();
int result[]=new int[2];
for(int i=0;i<nums.length;i++){
int num=target-nums[i];
if(map.containsKey(num)){
result[0]=map.get(num);
result[1]=i;
return result;
}
map.put(nums[i],i);
}
return result;
}
}
PHP實現:
<?php
function twoSum($nums,$target){
$result=array();
foreach ($nums as $key=>$value){
$num=$target-$nums[$key];
if ($i=array_search($num,$nums)){
$result[0]=$key;
$result[1]=$i;
return $result;
}
}
}
print_r(twoSum(array(7,3,4,7),7));