实验3
任务1:
#include<stdio.h> #include<stdlib.h> #include<time.h> #include<windows.h> #define N 80 void print_text(int line,int col,char text[]);//函数声明 void print_spaces(int n);//函数声明 void print_blank_lines(int n);//函数声明 int main(){ int line,col,i; char text[N]="hi,April~"; srand(time(0));//以当前的系统时间作为随机种子 for(i=1;i<=10;++i){ line=rand()%25; col=rand()%80; print_text(line,col,text); Sleep(1000);//暂停1000ms } return 0; } //打印n个空格 void print_spaces(int n){ int i; for(i=1;i<=n;++i) printf(" "); } //打印n行空白行 void print_blank_lines(int n){ int i; for(i=1;i<=n;++i) printf("\n"); } //在第line行第col列打印一段文本 void print_text(int line,int col,char text[]){ print_blank_lines(line-1);//打印(line-1)行空行 print_spaces(col-1);//打印(col-1)列空格 printf("%s",text);//在第line行、col列输出text中字符串 }
每隔1s输出一个Hi April~ 共输出10个。
任务2:
#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!=%11d\n",i,fac(i)); return 0; } long long fac(int n){ static long long p = 1; printf("p = %11d\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; }
总结:static变量只在第一次被定义,下一次使用该变量会获得上一次运算后的值。是静态储存的特点,只分配固定的储存空间。
任务3:
#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 func(int n) { long long a,b; if(n == 0) { a = 0; }else{ b = 2*func(n-1)+1; a = b; } return a; }
任务4:
#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 func(int n, int m){ int s; if(m == n||m == 0) s = 1; else if(m>n) s = 0; else s = func(n-1,m) + func(n-1,m-1); return s; }
任务5:
#include <stdio.h> double mypow(int x,int y); int main() { int x, y; double ans; while(scanf("%d%d", &x, &y) != EOF) { ans = mypow(x, y); printf("%d的%d次方: %g\n\n", x,y,ans); } return 0; } double mypow(int x,int y){ double t; double s; if(y>=0){ if(y == 0) s=1; else s=x*mypow(x,y-1); } else{ t = x*mypow(x,-y-1); s = 1/t; } return s; }
5.2:
#include <stdio.h> double mypow(int x,int y); int main() { int x, y; double ans; while(scanf("%d%d", &x, &y) != EOF) { ans = mypow(x, y); printf("%d的%d次方: %g\n\n", x,y,ans); } return 0; } double mypow(int x,int y){ int i; double s=1; if(y == 0){ s = 1; }else if(y>0){ for(i=1;i<=y;i++){ s = s*x;} }else{ for(i=1;i<=(-y);i++){ s = s/x;} } return s; }
任务6:
#include <stdio.h> void hanoi(unsigned int n,char from,char temp,char to); void moveplate(unsigned int n,char from,char to); int main() { unsigned int n; while(scanf("%u",&n) != EOF){ hanoi(n,'A','B','C'); int i,s,t=1; if(n>=1){ for(i = 1;i<=n;i++) t = 2*t; s = t-1; } printf("\n"); printf("一共移动了%d次\n",s); printf("\n");} return 0; } void hanoi(unsigned 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(unsigned int n,char from,char to) { printf("%u:%c-->%c\n",n,from,to); }
任务7:
#include<stdio.h> int is_prime(int x); int main() { int i, n; while (scanf("%d", &n) != EOF) { for (i = 2; i <= n; i++) { if (!is_prime(i) || !is_prime(n - i))continue; printf("%d = %d + %d\n", n, i, n - i); break; } } return 0; } int is_prime(int x) { int i; for (i = 2; i *i<= x; i++) { if (x % i == 0) { return 0;} else { return 1; } } }
任务8:
#include <stdio.h> #include <math.h> long func(long s); int main(){ long s,t; printf("Enter a number: "); while(scanf("%ld",&s) != EOF){ t = func(s); printf("new number is: %ld\n\n",t); printf("Enter a number: "); } return 0; } long func(long s) { long ans,z=0,q=0,j; for(;s!=0;) { ans = s % 10; s = s / 10; if(ans%2 != 0) z = z*10 +ans; } for(;z!=0;) { j = z % 10; z = z/10; q = q*10 + j; } return q; }