int n=10; while(n>7){n--; cout

int n=10; while(n>7){n--; cout
int n=10; while(n>7){n--; cout

int n=10; while(n>7){n--; cout
step1: n = 10 > 7 ,n--,n=9,输出9,
step2: n = 9 > 7, n--,n=8,输出8,
step3: n = 8 > 7,n--,n=7,输出7,
step4: n = 7 = 7, end while!
就是输出：9,8,7,