diff --git a/T3.cpp b/T3.cpp
new file mode 100644
index 0000000..b969ad0
--- /dev/null
+++ b/T3.cpp
@@ -0,0 +1,96 @@
+#include <stdio.h>
+
+#define SIZE 9  
+void printMatrix(int matrix[SIZE][SIZE]) {
+    int i,j;
+    for (i = 0; i < SIZE; i++) {
+        for (j = 0; j < SIZE; j++) {
+            printf("%d ", matrix[i][j]);
+        }
+        printf("\n");
+    }
+}
+int checkRow(int matrix[SIZE][SIZE], int row) {
+    int seen[SIZE + 1] = {0}; 
+    int col; 
+    for (col = 0; col < SIZE; col++) {
+        int num = matrix[row][col];
+        if (num != 0) {
+            if (seen[num]) {
+                printf("The number %d in the row %d has been used!\n", num, row + 1);
+                return 0; 
+            }
+            seen[num] = 1;
+        }
+    }
+    return 1;
+}
+int checkCol(int matrix[SIZE][SIZE], int col) {
+    int seen[SIZE + 1] = {0};  
+    int row;
+    for (row = 0; row < SIZE; row++) {
+        int num = matrix[row][col];
+        if (num != 0) {
+            if (seen[num]) {
+                printf("The number %d in the col %d has been used!\n", num, col + 1);
+                return 0;  
+            }
+            seen[num] = 1;
+        }
+    }
+    return 1;
+}
+int checkBlock(int matrix[SIZE][SIZE], int block) {
+    int seen[SIZE + 1] = {0};  
+    int startRow = (block / 3) * 3;
+    int startCol = (block % 3) * 3;
+    int i,j;
+    for (i = 0; i < 3; i++) {
+        for (int j = 0; j < 3; j++) {
+            int num = matrix[startRow + i][startCol + j];
+            if (num != 0) {
+                if (seen[num]) {
+                    printf("The number %d in the block %d has been used!\n", num, block + 1);
+                    return 0;  
+                }
+                seen[num] = 1;
+            }
+        }
+    }
+    return 1;
+}
+int main() {
+    int matrix[SIZE][SIZE] = {
+{8, 3, 0, 0, 7, 0, 0, 0, 0}, 
+{6, 0, 0, 1, 9, 5, 0, 0, 0}, 
+{0, 9, 8, 0, 0, 0, 0, 6, 0}, 
+{8, 0, 0, 0, 6, 0, 0, 0, 3}, 
+{4, 0, 0, 8, 0, 3, 0, 0, 1}, 
+{7, 0, 0, 0, 2, 0, 0, 0, 6}, 
+{0, 6, 0, 0, 0, 0, 2, 8, 0}, 
+{0, 0, 0, 4, 1, 9, 0, 0, 5}, 
+{0, 0, 0, 0, 8, 0, 0, 7, 9}};
+
+
+    printf("The original Sudoku matrix:\n");
+    printMatrix(matrix);
+    for (int i = 0; i < SIZE; i++) {
+        if (!checkRow(matrix, i)) {
+            printf("False: Invalid initial Sudoku matrix!\n");
+            return 0;
+        }
+        if (!checkCol(matrix, i)) {
+            printf("False: Invalid initial Sudoku matrix!\n");
+            return 0;
+        }
+    }
+    for (int block = 0; block < SIZE; block++) {
+        if (!checkBlock(matrix, block)) {
+            printf("False: Invalid initial Sudoku matrix!\n");
+            return 0;
+        }
+    }
+
+    printf("True: Valid initial Sudoku matrix!\n");
+    return 0;
+}