实验四
#define _CRT_SECURE_NO_DEPRECATE #include <stdio.h> long long fun(int n); int main() { int n; long long f; while (scanf("%d", &n) != EOF) { f = fun(n); printf("n = %d, f = %lld\n", n, f); } return 0; } long long fun(int n) { if (n == 1) return 1; else return 2 * fun(n - 1) + 1; }
#include <stdio.h> long long fac(int n); // 函数声明 int main() { int i,n; printf("Enter n: "); scanf("%d", &n); for(i=1; i<=n; ++i) printf("%d! = %lld\n", i, fac(i)); return 0; } // 函数定义 long long fac(int n) { static long long p = 1; p = p*n; printf("p = %lld\n", p); return p; }
#define _CRT_SECURE_NO_DEPRECATE #include<stdio.h> int func(int, int); int main() { int k = 4, m = .1, p1, p2; p1 = func(k, m); p2 = func(k, m); printf("%d,%d\n", p1, p2); return 0; } int func(int a, int b) { static int m = 0, i = 2; i += m + 1; m = i + a + b; return (m); }
当函数退出时,变量始终存在,但不能被其他函数使用,并且再次进入该函数时,将保存上次的结果。
#define _CRT_SECURE_NO_DEPRECATE #include <stdio.h> #include <stdlib.h> #define N 1000 int fun(int n,int m,int bb[N]) { int i,j,k=0,flag; for(j=n;j<=m;j++) { flag=j; for(i=2;i<j;i++) if(flag%i==0) { flag=0; break; } if(flag!=0) bb[k++]=j; } return k; } int main() { int n=0,m=0,i,k,bb[N]; scanf("%d",&n); scanf("%d",&m); for(i=0;i<m-n;i++) bb[i]=0; k=fun(n,m,bb); for(i=0;i<k;i++) printf("%4d",bb[i]); return 0; }
#define _CRT_SECURE_NO_DEPRECATE #include <stdio.h> void dec2n(int x, int n); int main() { int x; printf("输入一个十进制整数: "); scanf("%d", &x); dec2n(x, 2); dec2n(x, 8); dec2n(x, 16); return 0; } void dec2n(int x, int n) { int i,j,a,c; char b[100]; a = x; c = x; for(i=1;x;i++) x /= n; for(j=1;j<i;j++) { c = (a % n); a /= n; b[j] = c; } if(b[j]>9) switch(b[j]) { case 10:b[j]='A';break; case 11:b[j]='B';break; case 12:b[j]='C';break; case 13:b[j]='D';break; case 14:b[j]='E';break; case 15:b[j]='F';break; } for(x=i-1;x>0;x--) printf("%X",b[x]); printf("\n"); }