2016年海淀区中小学生信息学奥林匹克竞赛解题

1.价钱统计：

正确代码：

#include <iostream>

using namespace std;
int main( )
{
    float wm, p, g, a;
    float wm_price, p_price, g_price, a_price;
    float total_price = 0;
    cin>>wm>>p>>g>>a;
    wm_price = (int(wm*1.2*10+0.5)/10.0);
    p_price = (int(p*3.5*10+0.5)/10.0);
    g_price = (int(g*4.5*10+0.5)/10.0);
    a_price = (int(a*5*10+0.5))/10.0;
    total_price =(wm_price + p_price + g_price + a_price); 
    cout<<wm_price<<endl;
    cout<<p_price<<endl;
    cout<<g_price<<endl;
    cout<<a_price<<endl;
    cout<<total_price;
    //system("PAUSE");
    return 0;
}

2.打印图形：

正确代码：

#include <iostream>

using namespace std;

void print(int n)//空格函数：建议背下来！ 
{
    for(int x=0; x<n; x++)
        cout<<" "; 
}
int main()
{
    int i, j, k, l;
    char zimu;
    cin>>zimu;
    for(i=0; i<int(zimu)-64; i++)
    {
        print(i);
        for(j=i; j<int(zimu)-64; j++)
            cout<<char(int(zimu)-j);    
            
        for(k=int(zimu)-64-1; k>=i+1; k--)
            cout<<char(int(zimu)-k);
        cout<<endl;            
    }
} 

3.数列计算：

正确代码：

#include <iostream>

using namespace std;
int main( )
{
    float fenzi[31]={3,4,7};
    float fenmu[31]={4,7,11};
    int n; 
    float sum = 0;
    cin>>n;
    
    for(int i=2; i<=n; i++)
    {
        fenzi[i+1]=fenzi[i-1]+fenzi[i];
        fenmu[i+1]=fenmu[i-1]+fenmu[i];     
    }
    
    cout<<fenzi[n]<<"/"<<fenmu[n]<<endl;
    
    for(int i=1; i<=n; i++)
        sum =sum + (fenzi[i]/fenmu[i]);    
        
    cout<<int((sum)*100+0.5)/100.0;
    return 0;
}

#include<stdio.h>
int main()
{
	int n,i,f[31];
	double s=0.00;
	scanf("%d",&n);
	f[0]=4;
	f[1]=7;
	for(i=1;i<=n;i++)
	{
		s+=double(double(f[i-1])/double(f[i]));
		f[i+1]=f[i]+f[i-1];
	}
	printf("%d/%d
%.2f",f[n-1],f[n],s);
}

4.单词排序：

正确代码：

/*
C++ vector用法:
http://www.cnblogs.com/wang7/archive/2012/04/27/2474138.html
*/
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>

using namespace std;

int main( ) 
{    
    int n;    
    cin>>n;    
    vector<string> s(n);    
    for (int i=0; i<n; i++) 
        cin>>s[i];    
    sort(s.begin(), s.end());    
    for (int i=0; i<n; i++) 
        cout<<s[i]<<" ";       
    return 0;
}

/*

input:
5
apple duty sense mom dark

output:
apple dark duty mom sense
 
*/

5.评奖：

#include "stdio.h"
#include "stdlib.h"
//#include "algorithm.h"

struct stu
{
    char name[20]; 
    int math;
    int Chinese;
    int English;
    int Geography;
    int sum;
}; 

int main( )
{
     struct stu a[1000],temp;
     int n,i,j;
     scanf("%d",&n);
     
     for(i=0;i<n;i++)
     {
         scanf("%s%d%d%d%d",&a[i].name,&a[i].math,
             &a[i].Chinese,&a[i].English,&a[i].Geography);
           a[i].sum = a[i].math + a[i].Chinese + 
              a[i].English + a[i].Geography;
    }
                              
     for(i=0;i<n;i++)
     {
         for(j=0;j<n-1;j++)
         {
             if(a[j+1].sum>a[j].sum)
            {
                 temp=a[j];
                 a[j]=a[j+1];
                 a[j+1]=temp;
             }
         }
     }
     
     for(i=0;i<3;i++)
         printf("%s
",a[i].name);
     return 0;
}

/*
Input输入：
4
jing 98  90  87  74
ming 96  92  85  97
jun 95  78  56  91
hong 95  100  85  78

Output输出： 
ming
hong
jing
*/

6.附加字符串代码：

#include <iostream>
#include <cstring>

using namespace std;

int main( )
{
    char a[1000], b[1000];
    cin>>a;    
    int len=strlen(a);
    cout<<len<<endl;
    for(int i=0;i<len;i++)
    {
        if(a[i]>='0' && a[i]<='9')
        {
            cout<<i+1<<endl;
            break;
        }
        else
        {
            cout<<"no"<<endl;
        }
    }
    strupr(a);
    cout<<a<<endl;
    return 0;
}