// Two pointers, one from head to tail, one from tail to head

vector<int> twoSum(vector<int>& numbers, int target) {

int index1=0, index2 = numbers.size()-1;

vector<int> res;

while(index1 < index2){

if(numbers[index1] + numbers[index2] == target){

res.push_back(index1+1);

res.push_back(index2+1);

break;

}

// Sum is greater than target

// need to reduce the sum

else if(numbers[index1] + numbers[index2] > target){

index2--;

}

// Sum is less than target

else{

index1++;

}

}

return res;

}