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Square Matrix Multiplication/main.cpp

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+#include <vector>
+#include <iostream>
+using std::size_t;
+
+std::vector<int> get_column(std::vector<std::vector<int>> input, int index){
+    std::vector<int> result;
+    for(int i = 0; i<input.size(); i++){
+        result.push_back(input[i][index]);
+    }
+    return result;
+}
+
+int multiply(std::vector<int> first, std::vector<int> second){
+    int result = 0;
+    for(int i = 0; i<first.size(); i++){
+        result += first[i] * second[i];
+    }
+    return result;
+}
+
+std::vector<std::vector<int>> matrix_multiplication(std::vector<std::vector<int>> &a, std::vector<std::vector<int>> &b, size_t n){
+    std::vector<std::vector<int>> result;
+    std::vector<int> row;
+    for(int i=0; i<n;i++){
+        for(int j=0; j<n; j++){
+            row.push_back(
+                multiply(a[i], get_column(b, j))
+            );
+        }
+        result.push_back(row);
+        row = {};
+    }
+    return result;
+}
+
+
+int main(){
+    std::vector<std::vector<int>> test1 = {{1,2},{3,4}};
+    std::vector<std::vector<int>> test2 = {{1,2},{3,4}};
+    std::vector<std::vector<int>> result = matrix_multiplication(test1, test2, 2);
+    std::cout << result[1][1];
+}
+