C语言入门练习 - 第二期 判断语句与循环语句（题解）

比赛地址：C语言入门练习 - 第二期 判断语句与循环语句

A、入门——基础语法（for）

#include<stdio.h>int main(){int n,i;scanf("%d",&n);for(i=1;i<=n;i++){printf("%d\n",i);}}

B、入门——基础语法（if）

#include<stdio.h>int main(){int a,b,c;scanf("%d%d%d",&a,&b,&c);if(a<b&&b<c){printf("%d %d %d",a,b,c);}if(a<c&&c<b){printf("%d %d %d",a,c,b);}if(b<a&&a<c){printf("%d %d %d",b,a,c);}if(b<c&&c<a){printf("%d %d %d",b,c,a);}if(c<a&&a<b){printf("%d %d %d",c,a,b);}if(c<b&&b<a){printf("%d %d %d",c,b,a);}return 0;}

C、入门——判断奇偶数

#include<stdio.h>#include<stdlib.h>#include<string.h>int main(){int t,n,b;char a[100];scanf("%d",&t);while(t--){scanf("%s",a);n=strlen(a);b=(a[n-1]-48)%2;if(b==0)printf("even\n");elseprintf("odd\n");}return 0;}

D、入门——质数判断

#include<stdio.h>#include<math.h>int isprime(int n){if(n < 2)return 0;for(int i = 2;i <= sqrt(n);i++){if(n % i == 0) return 0;}return 1;}int main(){int n;while(scanf("%d", &n) != EOF){if(isprime(n)){printf("YES\n");}else{printf("NO\n");}}return 0;}

E、倍数

#include<stdio.h>int main (){int a,b;scanf("%d%d", &a, &b);if (a%b==0||b%a==0)puts("Sao Multiplos");elseputs("Nao sao Multiplos");return 0;}

G、加薪

#include <stdio.h>int main(){double salary;scanf("%lf", &salary);double x;if (salary <= 400) x = 0.15;else if (salary <= 800) x = 0.12;else if (salary <= 1200) x = 0.1;else if (salary <= 2000) x = 0.07;else x = 0.04;printf("Novo salario: %.2lf\n", salary * (1 + x));printf("Reajuste ganho: %.2lf\n", salary * x);printf("Em percentual: %.0lf %%", x * 100);return 0;}

H、三角形类型

#include<stdio.h>int max(int x, int y){return x > y ? x : y;}int min(int x, int y){return x < y ? x : y;}int main(){double a,b,c;scanf("%lf%lf%lf", &a, &b, &c);double x,y,z;x=max(a,max(b,c));y=min(a,min(b,c));z=(a+b+c)-(x+y);//printf("%lf %lf %lf\n",x,y,z);if(x>=y+z){printf("NAO FORMA TRIANGULO\n");return 0;}if(x*x==y*y+z*z)printf("TRIANGULO RETANGULO\n");if(x*x>y*y+z*z)printf("TRIANGULO OBTUSANGULO\n");if(x*x<y*y+z*z)printf("TRIANGULO ACUTANGULO\n");if(x==y&&y==z)printf("TRIANGULO EQUILATERO\n");if(x==y&&x!=z||x==z&&z!=y||z==y&&z!=x)printf("TRIANGULO ISOSCELES\n");return 0;}

I、实验

#include<stdio.h>int main(){int n;scanf("%d", &n);int c = 0, r = 0, f = 0;for (int i = 0; i < n; i ++ ){int k;char t;scanf("%d %c", &k, &t); // scanf在读入字符时，不会自动过滤空格、回车、tabif (t == 'C') c += k;else if (t == 'R') r += k;else f += k;}int s = c + r + f;printf("Total: %d animals\n", s);printf("Total coneys: %d\n", c);printf("Total rats: %d\n", r);printf("Total frogs: %d\n", f);printf("Percentage of coneys: %.2lf %%\n", (double)c / s * 100);printf("Percentage of rats: %.2lf %%\n", (double)r / s * 100);printf("Percentage of frogs: %.2lf %%\n", (double)f / s * 100);return 0;}

J、连续整数相加

#include<stdio.h>int x,y,n;int main(){while(~scanf("%d",&n)){if(n<=0) continue;if(!x) x=n;else{y=n;break;}}printf("%d",(2*x+y-1)*y/2);}