C++作业5

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
double score[10],aver=0,MAX,MIN,sum=0,S;
int a[10],b[10],i,N,count1=0,count2=0,k=0,j=0;
cout<<"请输入小组人数:";
cin>>N;
cout<<"请输入成绩:";
for(i=0;i<N;i++)
{
cin>>score[i];
if(score[i]<0 || score[i]>100)
{
cout<<"成绩范围是0～100，请重新输入:";
i--;
}
}
aver=aver+score[0];
MAX=MIN=score[0];
for(i=1;i<N;i++)
{
if(score[i] > MAX)     MAX=score[i];
else if(score[i] < MIN)       MIN=score[i];
aver=aver+score[i];
}
aver=aver / N;
for(i=0;i<N;i++)
{
if(score[i]==MAX)
{
count1++;
a[k]=i;
k++;
}
else   if(score[i]==MIN)
{
count2++;
b[j]=i;
j++;
}
sum=sum+(score[i]-aver)*(score[i]-aver);
}
S=sqrt(sum / (N-1));
cout<<"该小组的最高成绩是"<<MAX<<",最低成绩是"<<MIN<<"，平均成绩是"<<aver<<endl;
cout<<"最高成绩和最低成绩的人数分别是"<<count1<<"  "<<count2<<endl;
cout<<"考得最高成绩同学学号:";
for(i=0;i<k;i++)
cout<<a[i]<<"  ";
cout<<endl<<"考得最低成绩同学学号:";
for(i=0;i<j;i++)
cout<<b[i]<<"  ";
cout<<endl;
cout<<"所有同学成绩的标准偏差:"<<S<<endl;
return 0;
}

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
char str[50];
int i=0,n=0,m=0,j=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<<"其中的其他字符个数是: "<<j<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
{
cout<<"请输入十个数：";
int A[10],sum1=0,sum2=0,i;
for(i=0;i<10;i++)
{
cin>>A[i];
}
for(i=0;i<10;i++)
{
if(A[i]>0)  sum1=sum1+A[i];
else if(A[i]<0)  sum2=sum2+A[i];
}
cout<<"正数的和是"<<sum1<<endl;
cout<<"负数的和是"<<sum2<<endl;
return 0;
}