实验3
#include <stdio.h> #include <stdlib.h> #include <time.h> #include <windows.h> #define N 80 void print_text(int line, int col, char text[]); void print_spaces(int n); void print_blank_lines(int n); int main() { int line, col, i; char text[N] = "hi, November~"; srand(time(0)); for(i = 1; i <= 10; ++i) { line = rand() % 25; col = rand() % 80; print_text(line, col, text); Sleep(1000); } return 0; } void print_spaces(int n) { int i; for(i = 1; i <= n; ++i) printf(" "); } void print_blank_lines(int n) { int i; for(i = 1; i <= n; ++i) printf("\n"); } void print_text(int line, int col, char text[]) { print_blank_lines(line-1); print_spaces(col-1); printf("%s", text); }
//在屏幕上输出跑动的小人
#include <stdio.h> long long fac(int n); 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; } long long fac(int n) { static long long p = 1; p = p * n; return p; }
#include <stdio.h> long long fac(int n); 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; } long long fac(int n) { static long long p = 1; printf("p = %lld\n", p); p = p * n; return p; }
#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; }
运行结果与我分析的一致。
静态局部变量在函数第一次被调用时第一次遇到该变量时进行初始化（若没有初始化语句，则默认为0），这也是唯一的一次初始化，此后该变量的初始化语句不会再被执行。
#include <stdio.h> long long func(int n); int main() { int n; long long f; while (scanf("%d", &n) != EOF) { f = func(n); printf("n = %d, f = %lld\n", n, f); } return 0; } long long comb(int n){ unsigned int m; if(n==0) m=1; else{ m=2*comb(n-1); } return m; } long long func(int n){ unsigned int result; result=comb(n); result--; return result; }
#include <stdio.h> int func(int n, int m); int main() { int n, m; while(scanf("%d%d", &n, &m) != EOF) printf("n = %d, m = %d, ans = %d\n", n, m, func(n, m)); return 0; } int comb(int n){ int i,p=1; for(i=1;i<=n;i++) p=p*i; return p; } int func(int n,int m){ int a,b,c; a=comb(n-1)/(comb(m)*comb(n-1-m)); b=comb(n-1)/(comb(m-1)*comb(n-1-m+1)); c=a+b; }
#include <stdio.h> int mul(int n, int m); int main() { int n, m; while(scanf("%d%d", &n, &m) != EOF) printf("%d * %d = %d\n", n, m, mul(n, m)); return 0; } int mul(int n,int m){ int t,result; if(n==0||m==0) result = 0; else result=n+mul(n,m-1); return result; }
#include<stdio.h> #include<stdlib.h> #include<math.h> void moveplate(int n,char from,char to); void hanoi(int n,char from,char temp,char to) { if(n==1) moveplate(n,from,to); else { hanoi(n-1,from,to,temp); moveplate(n,from,to); hanoi(n-1,temp,from,to); } } void moveplate(int n,char from,char to) { printf("%u:%c-->%c\n",n,from,to); } int main() { int n; int m,count; while(scanf("%u",&n)!=EOF){ hanoi(n,'A','B','C'); printf("\n"); m=pow(2,n); count=m-1; printf("一共移动了%d次",count); printf("\n"); } return 0; }
#include<stdio.h> #include<stdlib.h> #include<math.h> int is_prime(int n){ int i,a; for(i=2;i<=sqrt(n);++i) { if(n%i==0) { a=0; break; } } if(a==0) return 0; else return 1; } int main(){ int m,p,q,q_flag,p_flag,n,i; int t; for(t=4;t<=20;++t){ if(t%2==1) continue; else{ n=t; m=is_prime(n); if(m==1) exit(0); p=1; do{ p=p+1; q=n-p; p_flag=1; for(i=2;i<=sqrt(p);++i){ if(p%i==0){ p_flag=0; break; } } q_flag=1; for(i=2;i<=sqrt(q);++i) { if(q%i==0){ q_flag=0; break; } } }while(p_flag==0||q_flag==0); printf("%d=%d+%d\n",n,p,q); } } system("pause"); return 0; }
#include <stdio.h> long fun(long s); int main() { long s, t; printf("Enter a number: "); while (scanf("%ld", &s) != EOF) { t = fun(s); printf("new number is: %ld\n\n", t); printf("Enter a number: "); } return 0; } long fun(long s){ int m=0,t=1; int x=0; do { if(s%2!=0) { x=s%10*t+x; t*=10; } s=s/10; }while(s/2!=0||s==1); return x; }
