diff --git a/sudoku3.c b/sudoku3.c
new file mode 100644
index 0000000..9404927
--- /dev/null
+++ b/sudoku3.c
@@ -0,0 +1,121 @@
+/*-------------------*/
+/*实验：数独矩阵------*/
+/*3. 判断一个不完整的矩阵是否满足“数独矩阵”的定义：*/
+/*-------------------*/
+#include<stdio.h>
+#include<stdlib.h>
+#include<time.h>
+void randseedInit(){
+    srand(time(NULL));
+}
+void makeNSeq(int _seq[],int n){//产生1-n的不重复序列（传入一个数组名指针）
+    int ct[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
+    int i; 
+    for ( i = 0; i < n; i++) {
+        int t = rand() % n;
+        while(ct[t=rand() % n]);
+        ct[t]++;
+        _seq[i] = t+1;
+    }
+}
+void initBoard(int _board[9][9]){
+	int i,j;
+    for ( i = 0; i < 9;i++)
+        for ( j = 0; j < 9;j++)
+            _board[i][j] = 0;
+}
+void makeRandomBoard(int _board[9][9]){
+    initBoard(_board);
+    int i_1;
+    for (i_1 = 0; i_1 < 3;i_1++){
+        int seq[9];
+        makeNSeq(seq, 9);
+        int i;
+        for (i = 0; i < 3;i++){
+            int where[9];
+            makeNSeq(where, 9);
+            int idx;
+            for ( idx = 0; idx < 3;idx++){
+                _board[i_1 * 3 + i][where[idx+i*3]-1] = seq[idx+i*3];
+            }
+        }
+    }
+}
+void printWhyInvalid(int num,int is_col,int index,int *needprint){
+    if(*needprint){
+        printf("False:Invalid initial Sudoku matrix!\n      The number %d in the %s %d has been used!\n", num, (is_col ? "col" : "block"), index);
+        *needprint = 0;
+    };
+}
+int whoBeUsedInSeq(int seq[9]){
+    int ct[10]={0,0,0,0,0,0,0,0,0,0};
+    int i;
+    for ( i = 0; i < 9;i++){
+        ct[seq[i]]++;
+    }
+    for (i = 1; i < 10;i++){
+        if(ct[i]>1)
+            return i;
+    }
+    return 0;
+}
+void matrixT(int _board[9][9],int _output[9][9]){
+	int i,j;
+    for ( i = 0; i < 9;i++)
+        for ( j = 0; j < 9;j++)
+            _output[j][i] = _board[i][j];
+}
+void resortByBlock(int _board[9][9], int _output[9][9]) {
+	int i,j;
+    for ( i = 0; i < 9;i++){
+        int p1x = i / 3;
+        int p1y = i % 3;
+        for ( j = 0; j < 9; j++){
+            int p2x = j / 3;
+            int p2y = j % 3;
+            _output[i][j] = _board[p1x * 3 + p2x][p1y * 3 + p2y];
+        }
+    }
+}
+int judgeValidInit(int _board[9][9]){
+    int needprint = 1;
+    int boardT[9][9];
+    int boardB[9][9];
+    matrixT(_board, boardT);
+    resortByBlock(_board, boardB);
+    int i;
+    for ( i = 0; i < 9;i++){
+        int who = whoBeUsedInSeq(boardT[i]);
+        if(who)
+            printWhyInvalid(who, 1, i+1, &needprint);
+        who = whoBeUsedInSeq(boardB[i]);
+        if(who)
+            printWhyInvalid(who, 0, i+1, &needprint);
+    }
+    return needprint;
+}
+void printBoad(int _board[9][9]){
+	int i,j;
+    for ( i = 0; i < 9;i++){
+        if(!(i%3))printf("|-----------------------|\n");
+        for ( j = 0; j < 9;j++){
+            if(!(j%3))
+                printf("| ");
+            if(_board[i][j]==0)
+                printf(". ");
+            else 
+                printf("%d ", _board[i][j]);
+        }
+        printf("|\n");
+    }
+    printf("|-----------------------|\n");
+}
+int main(){
+    randseedInit();
+    int board[9][9];
+    makeRandomBoard(board);
+    printf("The original Sudoku matrix:\n");
+    printBoad(board);
+    if(judgeValidInit(board))printf("True:Valid initial Sudoku matrix!\n");
+    
+}