估计楼主和我是差不多的样子,而6楼写对于我来说是太过深奥了.......看不明白，因为有好多东东还没学， 想必楼主也好多看不懂吧。我用我暂时学的东东还是写出来的，楼主该看得懂的

main()

{

long int n=1,i,t,sum=0;

for(i=1,t=1;n<=10;n=n+1)

{

while(t<=n)

{ i=i*t;

t=t+1; }

sum=sum+i;

}

printf("sum=%ld",sum);

getch();

}

我自己搞半天原来是数据类型没有用long型。 PS: getch();是用WIN-TC才要加的一个东东。

第一题 #include <stdio.h> #include <conio.h>

double factorial(int n);

void main() { int i; double sum = 0; for(i = 0; i <= 20; i++) { sum += factorial(i); }

printf("The result is %.0f",sum); getch(); }

double factorial(int n) { int i; double result = 1; for(i = 1; i <= n; i++) { result *= i; }

return result; } 第二题 #include <stdio.h> #include <ctype.h> #include <string.h> #include <conio.h>

void main() { int num_count = 0; int alpha_count = 0; int space_count = 0; int other = 0;

char *s; printf("Input a string:"); gets(s);

while(*s != '\0') { if(isdigit(*s)) num_count++; else if(isalpha(*s)) alpha_count++; else if(isspace(*s)) space_count++; else other++; s++; }

printf("The number of number is %2d\n",num_count); printf("The number of alpha is %2d\n",alpha_count); printf("The number of space is %2d\n",space_count); printf("The number of other symbolic is %2d\n",other);

getch(); } 第三题 #include <stdio.h> #include <conio.h>

void main() { int center = 3,i,j,k; int d = 5; char square[7][7];

for(i = 0; i < 7; i++) square[align=center][i] = '*';

j = center + 1; for(i = center-1; i >= 0; i--) { for(k = (7-d)/2; k < (7-d)/2+d; k++) { square[i][k] = '*'; square[j][k] = '*'; } d -= 2; j++; }

for(i = 0; i < 7; i++) { for(j = 0; j < 7; j++) { if(square[i][j] == '*') { printf("%4c",square[i][j]); } else { printf(" "); } } printf("\n"); }

getch(); }