diff --git a/矩阵4.c b/矩阵4.c
new file mode 100644
index 0000000..24689ff
--- /dev/null
+++ b/矩阵4.c
@@ -0,0 +1,369 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+#include <stdbool.h>
+void b(int board[][9])
+{
+	printf("|-----------------------|\n");
+for(int i=0;i<=8;i++)
+{
+	printf("| ");
+	for(int j=0;j<=8;j++)
+	{
+		printf("%d ",board[i][j]);
+		if(j==2||j==5)
+		printf("| ");
+	}
+	printf("|\n");
+	if(i==2||i==5)
+	printf("|-----------------------|\n");
+}
+printf("|-----------------------|\n");
+}
+void bb(int board[][9])
+{
+	srand(time(NULL));
+	int board[9][9]={0};
+	for(int i=1;i<=9;i++)
+	{
+		int x,y;
+	while(1)
+	{
+		
+		x=rand()%10;
+		y=rand()%10;
+		
+		if((x>=0&&x<=2)&&(y>=0&&y<=8))
+		{
+			int a=0;
+			for(int j=0;j<=8;j++)
+			{
+				if(board[x][j]!=0)
+				a++;
+			}
+			if(a<3&&board[x][y]==0)
+			{
+			board[x][y]=i;
+            break;
+		    }
+		}
+	}
+    }
+    for(int i=1;i<=9;i++)
+	{
+		int x,y;
+	while(1)
+	{
+		
+		x=rand()%10;
+		y=rand()%10;
+		
+
+		if((x>=3&&x<=5)&&(y>=0&&y<=8))
+		{
+			int a=0;
+			for(int j=0;j<=8;j++)
+			{
+				if(board[x][j]!=0)
+				a++;
+			}
+			if(a<3&&board[x][y]==0)
+			{
+			board[x][y]=i;
+			break;
+		}
+		}
+	}
+}
+for(int i=1;i<=9;i++)
+	{
+		int x,y;
+	while(1)
+	{
+		
+		x=rand()%10;
+		y=rand()%10;
+		if((x>=6&&x<=8)&&(y>=0&&y<=8))
+		{
+			int a=0;
+			for(int j=0;j<=8;j++)
+			{
+				if(board[x][j]!=0)
+				a++;
+			}
+			if(a<3&&board[x][y]==0)
+			{
+			board[x][y]=i;
+			break;
+		}
+		}
+	}
+}
+	b(board);
+    
+}
+int w(int board[][9])
+{
+	int judge=0;
+	flag1:
+	if(judge==0)
+	{
+	for(int i=0;i<9;i++)
+	{
+		for(int j=0;j<9;j++)
+		{
+			if(board[i][j]!=0)
+			{
+				for(int m=0;m<9;m++)
+				{
+					if(board[i][m]==board[i][j]&&m!=j)
+					{
+						judge=1;
+						goto flag1;
+					}
+				}
+			}
+		}
+	}
+    }
+    flag2:
+	if(judge==0)
+	{
+		for(int i=0;i<9;i++)
+    	{
+		for(int j=0;j<9;j++)
+		{
+			if(board[j][i]!=0)
+			{
+				for(int m=0;m<9;m++)
+				{
+					if(board[m][i]==board[j][i]&&m!=j)
+					{
+						judge=1;
+						goto flag2;
+					}
+				}
+			}
+		}
+    	}
+	}
+	flag3:
+	if(judge==0)
+	{
+		for(int i=0;i<=6;i=i+3)
+		{
+			for(int j=0;j<=6;j=j+3)
+			{
+				for(int x=i;x<i+3;x++)
+				{
+					for(int y=j;y<j+3;y++)
+					{
+						if(board[x][y]!=0)
+						{
+							for(int m=i;m<i+3;m++)
+							{
+								for(int n=j;n<j+3;n++)
+								{
+									if(board[m][n]==board[x][y]&&(m!=x||n!=y))
+									{
+										judge=1;
+										goto flag3;
+									}
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	return judge;
+}
+void ww(int board1[][9])
+{
+	int u=1;
+	flag:
+	if(u=1)
+	{
+	int d=0,e=0,f=0;
+	for(int i=0;i<=8;i++)
+	{
+	int c[9]={0};
+	for(int j=0;j<=8;j++)
+	{
+		for(int k=1;k<=9;k++)
+		{
+		if(board1[i][j]==k)
+		c[k-1]++;
+		if(c[k-1]>1)
+		{
+			d=1;
+			printf("False:Invalid initial Sudoku matrix!");
+			printf("The number %d in the col %d has been used!",k,i+1);
+			break;
+		}
+	    }
+	    if(d==1)
+	    break;
+	}
+	
+	if(d==1)
+	break;
+    }
+if(d==1)
+{
+	u=0;
+	goto flag;
+}
+	for(int i=0;i<=8;i++)
+	{
+	int c[9]={0};
+	for(int j=0;j<=8;j++)
+	{
+		for(int k=1;k<=9;k++)
+		{
+		if(board1[j][i]==k)
+		c[k-1]++;
+		if(c[k-1]>1)
+		{
+			e=1;
+			printf("False:Invalid initial Sudoku matrix!");
+			printf("The number %d in the row %d has been used!",k,i+1);
+			break;
+		}
+	    }
+	    if(e==1)
+	    break;
+	}
+	if(e==1)
+	break;
+    }
+    if(e==1)
+    {
+    	u=0;
+    	goto flag;
+	}
+	for(int i=0;i<=6;i=i+3)
+	{
+		for(int j=0;j<=6;j=j+3)
+		{
+			int r;
+			if(i==0&&j==0)
+			r=1;
+			if(i==0&&j==3)
+			r=2;
+			if(i==0&&j==6)
+			r=3;
+			if(i==3&&j==0)
+			r=4;
+			if(i==3&&j==3)
+			r=5;
+			if(i==3&&j==6)
+			r=6;
+			if(i==6&&j==0)
+			r=7;
+			if(i==6&&j==3)
+			r=8;
+			if(i==6&&j==6)
+			r=9;
+			int c[9]={0};
+			for(int g=i;g<=i+2;g++)
+			{
+				
+				for(int h=j;h<=j+2;h++)
+				{
+					for(int k=1;k<=9;k++)
+					{
+						if(board1[g][h]==k)
+						{
+							c[k-1]++;
+							if(c[k-1]>1)
+							{
+								f=1;
+								printf("False:Invalid initial Sudoku matrix!");
+			                    printf("The number %d in the block %d has been used!",k,r);
+			                    break;
+							}
+						}
+					}
+					if(f==1)
+					break;
+				}
+				if(f==1)
+					break;
+			}
+			if(f==1)
+					break;
+		}
+		if(f==1)
+					break;
+	}
+	if(d==0&&e==0&&f==0)
+	printf("True:Valid initial Sudoku matrix!\n");
+    }
+}
+bool p(int board[][9])
+{
+	int n=10,m=10;
+	flag:
+	if(n==10)
+	{
+	for(int i=0;i<9;i++)
+	{
+		for(int j=0;j<9;j++)
+		{
+			if(board[i][j]==0)
+			{
+				n=i;
+				m=j;
+				goto flag;
+			}
+			if(i==8&&j==8)
+			return true;
+		}
+	}
+    }
+	for(int x=1;x<=9;x++)
+	{
+		board[n][m]=x;
+		int c=w(board);
+		board[n][m]=0;
+		if(c==0)
+		{
+			board[n][m]=x;
+			if(p(board))
+			return true;
+			board[n][m]=0;
+		}
+	}
+	return false;
+}
+int main()
+{
+	int board[9][9]={{5, 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");
+		b(board);
+		ww(board);
+	int n=w(board);
+	if(n==1)
+	printf("No Solution!\n");
+	else
+	if(p(board))
+	{
+		printf("The solution of Sudoku matrix:\n");
+		p(board);
+		b(board);
+	}
+	else
+	printf("No Solution!\n");
+	return 0;
+}