实验3 C语言分支语句和循环语句编程应用(友好猜日期^_^)
实验任务一
#include <stdio.h> #include <math.h> int main(){ float a, b, c, x1, x2; float delta, real, imag; printf("Enter a, b, c: "); while(scanf("%f%f%f", &a, &b, &c) != EOF) { if(a == 0) printf("not quadratic equation.\n\n"); else { delta = b*b - 4*a*c; if(delta >= 0) { x1 = (-b + sqrt(delta)) / (2*a); x2 = (-b - sqrt(delta)) / (2*a); printf("x1 = %.2f, x2 = %.2f\n\n", x1, x2); } else { real = -b/(2*a); imag = sqrt(-delta) / (2*a); printf("x1 = %.2f + %.2fi, x2 = %.2f - %.2fi\n\n", real, imag, real, imag); } } printf("Enter a, b, c: "); } return 0; }
实验任务二
#include <stdio.h> #include <stdlib.h> #include <time.h> #define N 5 int main (){ int x,n; srand(time(0)); n=0; do { n++;x= rand()%10; printf("%3d",x); }while(n<N); printf("\n"); return 0; }
实验任务三
#include <stdio.h> int main (){ int x=101; int n=200; int num=0; for (;x<=200;x++){ int t,flag; flag=1; for (t=2;t<x;t++) { if (x%t==0) {flag=0; } } if (flag){ printf(" %d",x); num++; if (num%5==0) printf("\n"); } } printf("\n101~200之间共有%d个素数",num); return 0; }
实验任务四
#include <stdio.h> int main(){ long s; printf("Enter a number: "); while (scanf("%ld",&s)!=EOF){ long sum,t; sum=0; int a,b; b=0; t=10; long j=10; if (s<1000000000){ while (s/t!=0){ a=(s%t-b)/(t/10); b=b+a*(t/10); if(a%2!=0){ sum=sum+a*(j/10); j=j*10; } t=t*10; } a=(s%t-b)/(t/10); b=b+a*(t/10); if(a%2!=0){ sum=sum+a*(j/10); } }else{ int x; for (x=1;x<=9;x++){ a=(s%t-b)/(t/10); b=b+a*(t/10); if(a%2!=0){ sum=sum+a*(j/10); j=j*10; } t=t*10; } a=s/1000000000; if(a%2!=0){ sum=sum+a*(j/10); } } printf("new number is: %ld\n\n",sum); printf("Enter a number: "); } return 0; }
实验任务五
#include <stdio.h> int main(){ int n; printf ("Enter n(1~10):"); while (scanf ("%d",&n)!=EOF){ int t,f,T; f=1; T=1; double s=0.0; for (t=1;t<=n;t++){ T=t*T; s=s+f*(1.0/T); f=f*(-1); } printf("n = %d, s = %f\n\n",n,s); printf ("Enter n(1~10):"); } }
实验任务六
#include <stdio.h> #include <stdlib.h> #include <windows.h> int main (){ printf("猜猜2020年12月哪一天会是你的luck day\n\n"); int n= rand()%31+1; int t=1; printf ("开始喽,你有三次机会,猜吧(1~31):"); int a; for (t=1;t<=3;t++){ scanf("%d",&a); if(a<n){ printf("小伙子真着急,你猜的日期早了,luck day还妹到呢\n\n"); } if (a>n){ printf("你猜的日期晚啦,luck已经莫得了\n\n"); } if (a==n){ printf("这也能猜中??这么好的luck还需要luck day干嘛,速速去买彩票\n\n"); break; } } if(a!=n){ printf("次数用光啦。。。偷偷告诉你:"); Sleep(1000); printf("12月"); for (t=1;t<=3;t++){ Sleep(500); printf("。"); } Sleep(1000); printf("每天都是luck day!!!"); } }