Lookup table matrix keyboard

//"Table Lookup Method" and "Reverse Method". The table lookup method is the shortest program, but it takes up a little more time.
// A little storage space; the inversion method has the fastest execution speed, but requires the interface to be
//Bidirectional.
#include
#include 
#define uint unsigned int
#define uchar unsigned char
uchar code table[]={
~0x3F,~0x06,~0x5B,~0x4F,~0x66,
~0x6D,~0x7D,~0x07,~0x7F,~0x6F,
~0x77,~0x7C,~0x39,~0x5E,~0x79,~0x71}; //The common anode LED code is exactly opposite to the common cathode, so the cathode code is inverted
uchar num;
uchar keyscan();
/*void delay(uint z)
{
 uint x,y;
 for(x=z;x>0;x--)
  for(y=110;y>0;y--);
}*/
void main()
{
 P0=table[0];
 while(1)
 {
    num=keyscan();
    if(num!=16)
    P0=table[num];
  
 
 }
}
uchar keyscan()
{
 uchar code table1[3][4]=
  {//0xee,0xde,0xbe,0x7e,
   0xed,0xdd,0xbd,0x7d,
   0xeb,0xdb,0xbb,0x7b,
   0xe7,0xd7,0xb7,0x77};
  uchar temp1=0xfd,temp2,i,j; //If it is 3*4, just change the initial value of temp1 to p1^0 without setting 1 and changing the table value
  for(i=0;i<4;i++)//Scan the lower four bits//If 3*4 keyboard i<3 is also possible
  { P1=temp1; //Output a line of 0
   temp2=P1; //Read the status of P1 port immediately
   if((temp2&0xf0)!=0xf0)//If a key is pressed
   {
    for(j=0;j<4;j++)//Scan the upper four bits j=0 j=1 j=2 j=3  
   {
    if(temp2==table1[i][j])//look up table i=0 0 1 2 3
     return i*4+j; //If found, return the key value i=1 4 5 6 7
   } // i=2 8 9 10 11
   } // i=3 12 13 14 15
  else temp1=_crol_(temp1,1); //
          // i*4+j
  }
  return 16; //No code found, the return key is released
}