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+/*
+Challenge 206
+
+Task 2: Array Pairings
+Submitted by: Mohammad S Anwar
+
+You are given an array of integers having even number of elements..
+
+Write a script to find the maximum sum of the minimum of each pairs.
+Example 1
+
+Input: @array = (1,2,3,4)
+Output: 4
+
+Possible Pairings are as below:
+a) (1,2) and (3,4). So min(1,2) + min(3,4) => 1 + 3 => 4
+b) (1,3) and (2,4). So min(1,3) + min(2,4) => 1 + 2 => 3
+c) (1,4) and (2,3). So min(1,4) + min(2,3) => 2 + 1 => 3
+
+So the maxium sum is 4.
+
+Example 2
+
+Input: @array = (0,2,1,3)
+Output: 2
+
+Possible Pairings are as below:
+a) (0,2) and (1,3). So min(0,2) + min(1,3) => 0 + 1 => 1
+b) (0,1) and (2,3). So min(0,1) + min(2,3) => 0 + 2 => 2
+c) (0,3) and (2,1). So min(0,3) + min(2,1) => 0 + 1 => 1
+
+So the maximum sum is 2.
+*/
+
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+void compute_pairs_max(int& max,
+    const std::vector<int>& set, const std::vector<int>& pending
+) {
+    if (pending.size() == 0) {      // compute sum, set max
+        int sum = 0;
+        for (size_t i = 0; i < set.size(); i += 2) {
+            int n = std::min(set[i], set[i + 1]);
+            sum += n;
+        }
+        max = std::max(max, sum);
+    }
+    else {                          // recurse for each pair
+        for (size_t i = 0; i < pending.size() - 1; i++) {
+            for (size_t j = i+1; j < pending.size(); j++) {
+                std::vector<int> new_set = set;
+                std::vector<int> new_pending = pending;
+
+                new_set.push_back(pending[i]);
+                new_set.push_back(pending[j]);
+
+                new_pending.erase(new_pending.begin() + j);
+                new_pending.erase(new_pending.begin() + i);
+
+                compute_pairs_max(max, new_set, new_pending);
+            }
+        }
+    }
+}
+
+int main(int argc, char* argv[]) {
+    argv++; argc--;
+    if (argc % 2 != 0) {
+        std::cerr << "usage: ch-2 pairs..." << std::endl;
+        return EXIT_FAILURE;
+    }
+
+    std::vector<int> set;
+    std::vector<int> pending;
+    for (int i = 0; i < argc; i++)
+        pending.push_back(atoi(argv[i]));
+
+    int max = 0;
+    compute_pairs_max(max, set, pending);
+    std::cout << max << std::endl;
+
+    return EXIT_SUCCESS;
+}