9. #include void main() { int sum=0,n; scanf(\ while(n<=5) { sum+=n; n++; } printf(\ }
输入：1<回车>
10. #include void main() { int i, j; for(i=2;i>=0;i--) { for(j=1;j<=i;j++) printf(\ for(j=0;j<=2-i;j++) printf(\ printf(\ } }
11. #include void main() { int a,b; for(a=1,b=1;a<=100;a++) { if(b>20) break; if(b%4==1) b=b+4; } b=b-5; } printf(\ }
12. #include void main( )
{ continue; {
char k; int i;
for(i=1;i<3;i++) {
scanf(\ switch(k) {
case '0': printf(\ case '1': printf(\ } } }
输入：01<回车>
13. #include int main() { int i, s = 0; for(i = 1; i < 10; i++) { s += i * i; if(s > 10) break; } printf(\ return 0; }
14. #include void main() { char ch; while((ch=getchar())!='\\n') { if (ch>='A'&&ch<='Z') ch=ch+32; else if (ch>='a'&&ch<='z') ch=ch-32; printf(\ } } 输入：ABCdef<回车>
15. #include int main () { int a, b; for (a = 1, b = 1 ; a <= 100 ; a++)
{ if (b >= 9) break; if (b % 3 == 1) { b += 3 ; continue ; } b -= 5; } printf(\ return 0; }
16. #include int main () { int i = 0,j = 0; while (i < 10) i++; while (j++ < 10) ; printf(\ return 0; }
17. #include \ void main( ) { int i,j,t; for(i=1,j=10;i<3;i++,j--) t=i+j; t++; printf(\ }
18. #include \ void main() { int i=10,j; do { j = i%2; printf( \ i--; } while ( i> 4 ); }
19. #include \ void main() { int i=7,j; while ( i> 2) {
j = i%2; printf( \ i--; } printf( \ }
20. #include void main() { int i,j,t=0; for(i=3;i>0;i--) for(j=0;j<4;j++) t+=j; printf(\ }
解答: 1. 4321 2. 1 4 9 16
3. i=6,s=9 4. 1 2 3 4 5
5. sum=18
6. * ** *** **** 7. ## #### ###### ########
