第三周作业

作业1

# include <iostream>using namespace std;int main(){cout<<"number of bytes in int is: "<<sizeof(int)<<endl;cout<<"number of bytes in int is: "<<sizeof(long)<<endl;cout<<"number of bytes in int is: "<<sizeof(short)<<endl;cout<<"number of bytes in int is: "<<sizeof(float)<<endl;cout<<"number of bytes in int is: "<<sizeof(double)<<endl;return 0;}

作业2

#include <iostream>#include <iomanip>using namespace std;int main(){bool flag = true;cout<<flag<<endl;cout<<boolalpha<<flag<<endl;cout<<flag + 5<<endl;flag = 0;cout<<"执行语句flag=0;后flag的值为: "<<boolalpha<<flag<<endl;flag = 0.0;cout<<"执行语句flag=0.0;后flag的值为: "<<boolalpha<<flag<<endl;return 0;}

3

#include<iostream>using namespace std;int main(){int a,b,c,d;a=4;b=a;a=5;c=d=6;c*=a;d%=a+b;cout<<"a="<<a<<endl<<"b="<<b<<endl<<"c="<<c<<endl<<"d="<<d<<endl;return 0;}

4

# include<iostream>using namespace std;int main(){short i,j,m,n;i=1000;j=1000;m=i+j;n=i*j;cout<<"m="<<m<<endl;cout<<"n="<<n<<endl;return 0;}

5

#include<iostream>using namespace std;int main(){int i=6,j,k,temp;j=++i;k=i++;++i=1;cout<<"i="<<i<<endl<<"j="<<j<<endl<<"k="<<k<<endl;return 0;}

6

# include <iostream>using namespace std;int main(){int ab,ac;double b=3.14;char c='A';ab=int(b);ac=int(c);cout<<"b="<<b<<endl;cout<<"ab="<<ab<<endl;cout<<"c="<<c<<endl;cout<<"ac="<<ac<<endl;return 0;}

习题3

 

#include "stdafx.h"#include<iostream>#include<math.h>using namespace std;int main(){int e=1,f=4,g=2,a=7;float m=10.5,n=4.0,k;float x=2.5,y=4.7,z;k=(e+f)/g+sqrt((double)n)*1.2/g+m;z=x+a%3*(int(x+y)%2)/4;cout<<"k="<< k<<endl;cout<<"z="<< z<<endl;return 0;}

 三角形

 

# include <iostream># include <math.h>using namespace std;int main(){float a,b,c,d,e;double mianji,zhouchang;shuru:cout<<"请输入所求三角形的三条边"<<endl;cin>>a>>b>>c;if(a+c>b&&a+b>c&&c+b>a){d=(a*a+b*b-c*c)/(2*a*b);e=sqrt(1-d*d);mianji=0.5*a*b*e;zhouchang=a+b+c;cout<<"该三角形的面积为"<<mianji<<endl<<"该三角形的周长为"<<zhouchang<<endl;goto shuru;}else{cout<<"输入有错，请确认边长是否能构成三角形后重新输入"<<endl;goto shuru;}return 0;}