C++ 语法基础课 习题1 —— 变量、输入输出、顺序语句

课堂

1. Hello World

#include
#include

using namespace std;

int main()
{
    cout << "Hello World" << endl;
    
    bool false/true;    1byte 1字节   1Byte=8bit 1字节=8比特
    char 'a','b',' ','\n';  1byte
    int -2147483648~2147483647  4byte
    float 1.23,1.23e-2,6-7有效数字  4byte
    double 15-16有效数字    8byte
    
    long long -2^63~2^63-1  8byte
    long double 18到19位
    
    return 0;
}
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2. A + B

#include
#include

using namespace std;

int main()
{
    int a,b;
    scanf("%d%d",&a,&b);
    printf("a+b=%d\na*b=%d\n",a+b,a*b);
    
    char a,b;//会读入空格，所以输入中间不能有空格
    scanf("%c%c",&a,&b);
    printf("%c %c\n",a,b);
    
    // int:%d
    // float:%f
    // double:%lf
    // char:%c
    
    return 0;
}
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3. 浮点数的比较

#include
#include
using namespace std;

const double eps=1e-6

int main()
{
    double x = 1.23456789;
    double a = x*x;
    double b =sqrt(a);
    printf("%.10f\n",b);
    
    if(fabs(x-b)<eps) puts("相等");
    return 0;
}
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例题

1. A + B

AcWing 1.A+B

#include
using namespace std;

int main()
{
    int a,b;//定义两个变量
    cin>>a>>b;//输入
    cout<<a + b<<endl;
    return 0;
}
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2. 差

Acwing 608.差

#include
using namespace std;

int main()
{
    int a,b,c,d,X;
    cin>>a>>b>>c>>d;
    X = a*b-c*d;
    cout<< "DIFERENCA = "<< X <<endl;
    //99%评测器，会自动过滤最后一个回车和每一行结尾的空格
    return 0 ;
}
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3. 圆的面积

Acwing 604.圆的面积

#include
#include
using namespace std;

int main()
{
    double R,pi=3.14159;
    scanf("%lf",&R);
    printf("A=%.4lf\n",pi*R*R);
}
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4. 平均数1

Acwing 606.平均数1

#include
using namespace std;

int main()
{
    double a,b;
    scanf("%lf%lf",&a,&b);
    printf("MEDIA = %.5lf",(3.5*a+7.5*b)/11.0);
}
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5. 工资

Acwing 609.工资

#include
using namespace std;

int main()
{
    int a,b;
    double c;
    scanf("%d%d%lf",&a,&b,&c);
    printf("NUMBER = %d\nSALARY = U$ %.2lf",a,b*c);
}
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6. 油耗

Acwing 615.油耗

#include
using namespace std;

int main()
{
    int a;
    double b;
    scanf("%d%lf",&a,&b);
    printf("%.3lf km/l",a/b);
}
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7. 两点间的距离(cmath)

Acwing 616.两点间的距离

#include
#include
using namespace std;

int main()
{
    double x1,y1,x2,y2;
    scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
    printf("%.4lf\n",sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)));
    
    return 0;
}
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8. 钞票

Acwing 653.钞票

#include
using namespace std;

int main()
{
    int n;
    scanf("%d",&n);
    printf("%d\n",n);
   
    printf("%d nota(s) de R$ 100,00\n",n/100);
    n%= 100;
    printf("%d nota(s) de R$ 50,00\n",n/50);
    n%= 50;
    printf("%d nota(s) de R$ 20,00\n",n/20);
    n%= 20;
    printf("%d nota(s) de R$ 10,00\n",n/10);
    n%= 10;
    printf("%d nota(s) de R$ 5,00\n",n/5);
    n%= 5;
    printf("%d nota(s) de R$ 2,00\n",n/2);
    n%= 2;
    printf("%d nota(s) de R$ 1,00\n",n/1);
    
    return 0;
}
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9. 时间转换

Acwing 654.时间转换

#include
using namespace std;

int main()
{
    int n;
    scanf("%d",&n);
    printf("%d:%d:%d",n/3600,n%3600/60,n%3600%60);
    
    return 0;
}
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习题

1. 简单乘积

Acwing 605.简单乘积

#include
using namespace std;

int main()
{
    int a,b;//定义两个变量
    cin>>a>>b;//输入
    cout<<"PROD = "<< a*b<<endl;
    return 0;
}
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2. 简单计算

Acwing 611.简单计算

#include
#include
using namespace std;

int main()
{
    double n1,s1,p1;
    double n2,s2,p2;
    cin >> n1 >> s1 >> p1;
    cin >> n2 >> s2 >> p2;
    printf("VALOR A PAGAR: R$ %.2lf\n",s1*p1+s2*p2);
}
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3. 球的体积

Acwing 612.球的体积

#include
#include
using namespace std;

int main()
{
    double R,pi=3.14159;
    scanf("%lf",&R);
    printf("VOLUME = %.3lf\n",(4/3.0)*pi*R*R*R);
    return 0;
}
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4. 面积

Acwing 613.面积

#include
#include
using namespace std;

int main()
{
    double a,b,c,pi=3.14159;
    scanf("%lf%lf%lf",&a,&b,&c);
    printf("TRIANGULO: %.3lf\n",0.5*a*c);
    printf("CIRCULO: %.3lf\n",pi*c*c);
    printf("TRAPEZIO: %.3lf\n",0.5*(a+b)*c);
    printf("QUADRADO: %.3lf\n",b*b);
    printf("RETANGULO: %.3lf",a*b);
    
    return 0;
}
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5. 平均数2

Acwing 607.平均数2

#include
using namespace std;

int main()
{
    double a,b,c;
    scanf("%lf%lf%lf",&a,&b,&c);
    printf("MEDIA = %.1lf",(2*a+3*b+5*c)/10.0);
}
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6. 工资和奖金

Acwing 610.工资和奖金

#include
#include
#include

using namespace std;

int main()
{
    string name;
    cin >> name;
    double a,b;
    scanf("%lf\n%lf\n",&a,&b);
    printf("TOTAL = R$ %.2lf\n",a+b*0.15);
    
    return 0;
}
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7. 最大值

Acwing 614.最大值

#include
#include
#include

using namespace std;

int main()
{
    int a,b,c,m,n;// 用两次公式
    scanf("%d%d%d",&a,&b,&c);
    m = (a+b+abs(a-b))/2;
    n = (c+m+abs(c-m))/2;
    printf("%d eh o maior",n);
    
    return 0;
}
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8. 距离

Acwing 617.距离

#include
#include

using namespace std;

int main()
{
    int L,t;
    cin >> L;
    t = L*2;
    printf("%d minutos",t);
    
    return 0;
}
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9. 燃料消耗

Acwing 618.燃料消耗

#include
#include

using namespace std;

int main()
{
    double a,b;
    cin >>a >>b;
    printf("%.3lf",a*b/12.0);
    
    return 0;
}
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10. 钞票和硬币

Acwing 656.钞票和硬币

#include
#include
using namespace std;

//需要化为分来算
int main()
{
    double n;
    cin >> n;
    int m=n*100;
    cout << "NOTAS:"<<endl;
    cout<< m/10000 << " nota(s) de R$ 100.00"<<endl;
    m = m%10000;
    cout<< m/5000 <<" nota(s) de R$ 50.00"<<endl;
    m = m%5000;
    cout<< m/2000<<" nota(s) de R$ 20.00"<<endl;
    m = m%2000;
    cout<< m/1000<<" nota(s) de R$ 10.00"<<endl;
    m = m%1000;
    cout<< m/500<<" nota(s) de R$ 5.00"<<endl;
    m = m%500;
    cout<< m/200<<" nota(s) de R$ 2.00"<<endl;
    m = m%200;
    cout <<"MOEDAS:"<<endl;
    cout<< m/100<<" moeda(s) de R$ 1.00"<<endl;
    m = m%100;
    cout<< m/50<<" moeda(s) de R$ 0.50"<<endl;
    m = m%50;
    cout<< m/25<<" moeda(s) de R$ 0.25"<<endl;
    m = m%25;
     cout<< m/10<<" moeda(s) de R$ 0.10"<<endl;
    m = m%10;
     cout<< m/5<<" moeda(s) de R$ 0.05"<<endl;
    m = m%5;
     cout<< m/1<<" moeda(s) de R$ 0.01"<<endl;

    return 0;
}
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11. 天数转换

Acwing 655.天数转换

#include
using namespace std;

int main()
{
    int n;
    scanf("%d",&n);
    printf("%d ano(s)\n%d mes(es)\n%d dia(s)\n",n/365,n%365/30,n%365%30);
    
    return 0;
}
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