add function to max_size_index

Function to return the element index number of the vector with the largest length in a 2d array.

Author: rahanahu

max2darrayidx.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+//Function to return the element index number of the vector with the largest length in a 2d array.
+size_t max_size_index(vector<vector<int>> v) {
+    decltype(v)::iterator m = max_element(v.begin(), v.end(), [](vector<int> a, vector<int> b) {
+        return a.size() < b.size(); });
+    size_t index = std::distance(v.begin(), m);
+    return index;
+
+}
+
+
+
+
+
+int main() {
+    vector<vector<int>> array2d = { {1,2,3}, {4,5,6}, {7,8,9,10} };
+
+    auto i = max_size_index(array2d);
+    //return 2
+    cout << i << endl;
+	return 0;
+}