C++作业5

1.#include<iostream.h>    
 int main()    
{    
    const int N=10;    
    int a[N],b[N],c[N],i,j=0,k=0,s1=0,s2=0;    
     for(i=0;i<N;i++)    
    {    
        cin>>a[i];    
        if(a[i]>0)    
        {    
            c[j]=a[i];    
         j++;      
        }    
        else     
        {    
            b[k]=a[i];    
        k++;      
        }    
     }      
     cout<<"负数的和为:\n";  
    for(i=0;i<k;i++)    
        s1+=b[i] ;  
        cout<<s1<<endl;  
    cout<<"正数的和为:\n";  
    for(i=0;i<j;i++)    
        s2+=c[i];  
        cout<<s2<<endl;    
}
2.#include<iostream.h>    
#include<cstdio>      
using namespace std;    
int main()    
{    
    char str[50];    
    int i=0,n=0,j=0,m=0;    
    cout<<"输入字符串:";    
    gets(str);    
    while(str[i]!='\0')    
    {      
        if (str[i]>='0'&&str[i]<='9')   
            n++;   
        else if (str[i]>='a'&&str[i]<='z'||str[i]>='A'&&str[i]<='Z')  
            m++;  
        else j++;  
        i++;  
    }    
    cout<<"其中的数字个数是: "<<n<<endl;  
    cout<<"其中的字母个数是: "<<m<<endl;  
    cout<<"其中的其它字符个数是: "<<j<<endl;  
} 
3.#include<iostream.h>    
int main()  
{  
    int a[10],sum1=0,sum2=0,i;  
    cout<<"请输入十个数字："<<endl;  
    for(i=0;i<10;i++)  
    {  
        cin>>a[i];  
        if(a[i]>0)  
        sum1=a[i]+sum1;  
        else  
        sum2=a[i]+sum2;  
    }  
cout<<"数组中正数的和:"<<sum1<<endl;  
cout<<"数组中负数的和:"<<sum2<<endl;  
}