def find_pair(A, target):
 B = [[] for i in range(target + 1)]
 for i in range(0, len(A)):
 if A[i] <= target:
 B[A[i]].append(i)
 for i in range(0, target / 2 + 1):
 if len(B[i]) != 0 and len(B[target - i]) != 0:
 print(i, B[i], target-i, B[target-i])
 
if __name__ == "__main__":
 A = [0, 1, 1, 2, 11, 8, 3, 4, 5, 6, 7, 8, 9, 10]
 find_pair(A, 9)

def find_pair(A, target):
 B = {}
 for i in range(0, len(A)):
 if A[i] <= target:
 if not B.has_key(A[i]):
 B[A[i]] = [i]
 else:
 B[A[i]].append(i)
 for i in range(0, target / 2 + 1):
 if B.has_key(i) and B.has_key(target-i):
 print(i, B[i], target-i, B[target-i])
 
if __name__ == "__main__":
 A = [0, 1, 1, 2, 11, 8, 3, 4, 5, 6, 7, 8, 9, 10]
 find_pair(A, 9)

def find_pair(A, target):
 A.sort()
 i, j = 0, len(A) - 1
 while i < j:
 s = A[i] + A[j]
 if s == target:
 print(i, A[i], j, A[j])
 i += 1
 j -= 1
 elif s < target:
 i += 1
 else:
 j -= 1
 
if __name__ == "__main__":
 A = [0, 1, 1, 2, 11, 8, 3, 4, 5, 6, 7, 8, 9, 10]
 find_pair(A, 9)