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other/two_sum_advance.py

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+'''<----------------------------------------2 POINTER SOLUTION --------------------------------------->
+
+Given a 1-indexed array of integers numbers that is already sorted in non-decreasing order, find two numbers such that they add up to a specific target number. Let these two numbers be numbers[index1] and numbers[index2] where 1 <= index1 < index2 < numbers.length.
+Return the indices of the two numbers, index1 and index2, added by one as an integer array [index1, index2] of length 2.
+The tests are generated such that there is exactly one solution. You may not use the same element twice.
+Your solution must use only constant extra space.
+Example 1:
+
+Input: numbers = [2,7,11,15], target = 9
+Output: [1,2]
+Explanation: The sum of 2 and 7 is 9. Therefore, index1 = 1, index2 = 2. We return [1, 2].
+Example 2:
+
+Input: numbers = [2,3,4], target = 6
+Output: [1,3]
+Explanation: The sum of 2 and 4 is 6. Therefore index1 = 1, index2 = 3. We return [1, 3].
+Example 3:
+
+Input: numbers = [-1,0], target = -1
+Output: [1,2]
+Explanation: The sum of -1 and 0 is -1. Therefore index1 = 1, index2 = 2. We return [1, 2].
+
+
+#-------------------------CODE----------------# '''
+def two_sum(self, numbers: List[int], target: int) -> List[int]:
+    n = len(numbers)
+    l = 0 
+    r = n-1
+    res = []
+    while l<r:
+        if (numbers[l] + numbers[r] ==target):
+            res.append(l+1)
+            res.append(r+1)
+        if (numbers[l]+numbers[r]>target):
+            r-=1
+        else:
+            l+=1
+    res.sort()
+    return res
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()