南京邮电大学C语言程序设计网站上机习题参考答案

printf(\ printf(\ return 0; }

17. 编程题17：根据输入日期输出对应季节 #include

enum Seasons {Spring,Summer,Autumn,Winter}; struct Date { int year,month,day; };

int main( ) { struct Date d; enum Seasons s; scanf(\ if (d.month>=3&&d.month<=5) s=Spring; else if(d.month>=6&&d.month<=8) s=Summer; else if (d.month>=9&&d.month<=11) s=Autumn; else if(d.month==12||d.month==1||d.month==2) s=Winter; switch(s) { case Spring: printf(\ case Summer: printf(\ case Autumn: printf(\ case Winter: printf(\ } return 0;

}

18. 编程题18：进制转换 #include int input(char *s) { int i=0; char c; do { c=getchar(); if (c>='0'&&c<='9'||c>='A'&&c<='F'||c>='a'&&c<='f') s[i++]=c;

else return 0; }while (i<4); s[i]='\\0'; return 1; }

int change(char *s) { int n=0,i=0; while (s[i]) { if (s[i]>='0'&&s[i]<='9') n=n*16+(s[i]-48); else if(s[i]>='A'&&s[i]<='F') n=n*16+(s[i]-55); else if(s[i]>='a'&&s[i]<='f') n=n*16+(s[i]-87); i++; } return n; }

int main( ) { char s[5]; //定义字符数组 if (input(s)) //如果正确输入了四位十六进制数才进行转换并输出 printf(\ else //否则输出提示信息 printf(\ return 0; }

19. 编程题19：字符串逆置 #include #include void reverse(char *s) { char *p=s,*q,t; int len=strlen(s); q=p+len-1; while (p

*q=t; p++; q--; } }

int main( ) { char s[100]; gets(s); reverse(s); puts(s); return 0; }

20. 编程题20：字符串转换 #include

int change(char *source,char * des) { int i=0; while (*source) { if (*source>='0'&&*source<='9') des[i++]=*source; source++; } des[i]='\\0'; return i; }

double calcu(char *s) { double result=0; while (*s) { result=result*10+(*s-48); s++; } return result; }

int main( ) { char str[50],strdes[50]; gets(str); if (change(str,strdes)) printf(\ else

printf(\ return 0;

21. 编程题21：打印杨辉三角形 #include int main( ) { int y[10][10]={0},i,j,n; scanf(\ for (i=1;i<=n;i++) y[i][1]=y[i][i]=1; for (i=3;i<=n;i++) for (j=2;j

22. 编程题22：判断矩阵是否对称 #include #define N 4

int isSymmetrical(int (*p)[N]) { int i,j; for (i=0;i

int main( ) { int arr[N][N],i,j; for (i=0;i

}

23. 编程题23：字符串大小比较 #include #include

void Display(char pa[][20],int n) //输出n个字符串 { int i; for(i=0;i

void Selection(char pa[][20],int n) //选择排序函数定义 { int i,k,index; char temp[20]; for (k=0;k

int main( ) { char a[6][20]; int i; for( i=0; i<6; i++ ) gets(a[i]); Selection(a,6); Display(a,6); return 0; }