How to wrap the paper matrix if it is too long?

for(I = 0； I<4; i++)

b[I]= a[0][I]；

for(I = 0； I< 1; i++)

for(j = 0； j & lt4; j++)

a[I][j]= a[I+ 1][j]；

for(I = 0； I<4; i++)

a[2][I]= b[I]；

Revise as follows:

for(I = 0； I<4; I++)// Copy the value in the first row of the matrix to copy to the last row, otherwise it will be overwritten.

b[I]= a[0][I]；

for(I = 0； I<2; I++)// Moves the matrix up one row, which can be equal to 1.

for(j = 0； j & lt4; j++)

a[I][j]= a[I+ 1][j]；

for(I = 0； I<4; I++)// Copy the first line to the last line.

a[2][I]= b[I]；