diff --git a/3 b/3
new file mode 100644
index 0000000..9a31f4e
--- /dev/null
+++ b/3
@@ -0,0 +1,71 @@
+#include <iostream>
+#include <ctime>
+#include <cstdlib>
+
+
+const int SIZE = 1024;
+
+
+void matmul(float** A, float** B, float** C, int n) {
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < n; j++) {
+            float sum = 0;
+            for (int k = 0; k < n; k++) {
+                sum += A[i][k] * B[k][j];
+            }
+            C[i][j] = sum;
+        }
+    }
+}
+
+int main() {
+    
+    float** A = new float* [SIZE];
+    for (int i = 0; i < SIZE; i++) {
+        A[i] = new float[SIZE];
+    }
+
+    float** B = new float* [SIZE];
+    for (int i = 0; i < SIZE; i++) {
+        B[i] = new float[SIZE];
+    }
+
+    float** C = new float* [SIZE];
+    for (int i = 0; i < SIZE; i++) {
+        C[i] = new float[SIZE];
+    }
+
+
+    for (int i = 0; i < SIZE; i++) {
+        for (int j = 0; j < SIZE; j++) {
+            A[i][j] = (float)(rand() % 100);
+            B[i][j] = (float)(rand() % 100);
+        }
+    }
+
+    clock_t start_time, end_time;
+
+    start_time = clock();
+
+
+    matmul(A, B, C, SIZE);
+
+
+    end_time = clock();
+
+
+    double elapsed_time = ((double)(end_time - start_time)) / CLOCKS_PER_SEC;
+    std::cout << "基础矩阵乘法的运行时间：" << elapsed_time << " 秒" << std::endl;
+
+
+    for (int i = 0; i < SIZE; i++) {
+        delete[] A[i];
+        delete[] B[i];
+        delete[] C[i];
+    }
+    delete[] A;
+    delete[] B;
+    delete[] C;
+
+    return 0;
+}
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