Add solution for day-06

Author: Ayush Singh

Problems/Binary-Search/Day-06/sol/ayush2005k/notes.md

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+## Approach
+- Sort the wealth array
+- Target the middle index to ensure more than half are unhappy
+- Solve inequality directly instead of using binary search
+
+## Complexity
+- Time: O(n log n)
+- Space: O(n)

Problems/Binary-Search/Day-06/sol/ayush2005k/problem.md

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+## C. Robin Hood in Town
+
+Link: https://codeforces.com/contest/2014/problem/C
+
+Determine the minimum extra gold required so that
+strictly more than half of the population becomes unhappy.

Problems/Binary-Search/Day-06/sol/ayush2005k/solution.py

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+import sys
+input = sys.stdin.readline
+
+t = int(input())
+
+for _ in range(t):
+    n = int(input())
+    a = list(map(int, input().split()))
+
+    if n <= 2:
+        print(-1)
+        continue
+
+    a.sort()
+    total = sum(a)
+
+    k = n // 2
+    x = 2 * n * a[k] - total + 1
+
+    print(max(0, x))