int k = 5； while( - k)printf("%d "，k-= 3； ); The implementation process is:

K=5, then execute the while statement, because -before, execute the operation of subtracting 1 and then execute the judgment, k=4, execute the loop, k-=3, that is, k=k-3, output the value of subtracting 3, that is, 1, and then continue the while statement and execute the subtraction 1.