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diff --git a/challenge-011/paulo-custodio/cpp/ch-2.cpp b/challenge-011/paulo-custodio/cpp/ch-2.cpp
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+/*
+Challenge 011
+
+Challenge #2
+Write a script to create an Indentity Matrix for the given size. For example,
+if the size is 4, then create Identity Matrix 4x4. For more information about
+Indentity Matrix, please read the wiki page.
+*/
+
+#include <iostream>
+#include <vector>
+using namespace std;
+
+vector<vector<int>> identity_matrix(int n) {
+    vector<vector<int>> id;
+    for (int row = 0; row < n; row++) {
+        id.emplace_back();
+        for (int col = 0; col < n; col++)
+            id[row].push_back(col == row ? 1 : 0);
+    }
+    return id;
+}
+
+void print_matrix(ostream& os, vector<vector<int>>& m) {
+    os << "[";
+    const char* row_sep = "";
+    for (size_t row = 0; row < m.size(); row++) {
+        os << row_sep << "[";
+        row_sep = ",\n ";
+        const char* col_sep = "";
+        for (size_t col = 0; col < m[row].size(); col++) {
+            os << col_sep << m[row][col];
+            col_sep = ", ";
+        }
+        os << "]";
+    }
+    os << "]\n";
+}
+
+int main(int argc, char* argv[]) {
+    int n = 0;
+    if (argc == 2)
+        n = atoi(argv[1]);
+    if (n < 1)
+        n = 4;
+
+    vector<vector<int>> id = identity_matrix(n);
+    print_matrix(cout, id);
+}