学步园

                    这章的题应该都算是水题了，都是一些最基本入门的模拟，不涉及任何算法，LRJ老师为的就是让大家熟悉熟悉竞赛的入门和最简单的竞赛.只要认真的模拟和思考，然后结合书本前面讲的那些知识的灵活运用，分分秒秒不在话下、、、、

2-1  

# include<cstdio>
# include<iostream>

using namespace std;

int a,b,c;

int f( int x )
{
    a = x/100;
    b = x/10%10;
    c = x%10;
    if ( a*a*a+b*b*b+c*c*c == x )
    return 1;
    else
    return 0;

}

int main(void)
{
    //int a,b,c;
    for ( int i = 100;i < 200;i++ )
    {
        if(f(i))
        cout<<i<<endl;
        else
        continuel

    }

    return 0;
}

2-2

# include<cstdio>
# include<iostream>

using namespace std;

int main(void)
{
    int a,b,c;
    cin>>a>>b>>c;
    int cnt = 0;
    int flag = 1;
    for ( int i = 10;i <= 100;i++ )
    {
        if ( i%3==a&&i%5==b&&i%7==c )
        {
            cnt++;
            flag = 0;
            printf("Case %d %d",cnt,i);
        }

    }
    if ( flag)
            cout<<"No answer"<<endl;


    return 0;
}

2-3

# include<cstdio>
# include<iostream>

using namespace std;

int main(void)
{
    int n;cin>>n;
    int k = 0;
    for ( int i = 0;i < n;i++ )
    {
        k = i;
        for ( int j = 0;j < k;j++ )
            printf(" ");
            for ( int l = 0;l < 2*n-2*i-1;l++ )
                printf("#");
                    printf("\n");
    }


    return 0;
}

2-4

# include<cstdio>
# include<iostream>

using namespace std;

int main(void)
{
    int n,m;
    int cnt = 0;
    double o;
    while ( (scanf("%d%d",&n,&m)!=EOF)&&n!=0&&m!=0 )
    {
        double sum = 0;
        for ( int i = n;i <= m;i++ )
        {
            o = i;
            sum += 1.0/(o*o);
            //cout<<sum<<endl;
        }
        printf("Case %d: %.5lf",++cnt,sum);

    }


    return 0;
}

2-5

# include<cstdio>
# include<iostream>

using namespace std;

int main(void)
{
    int a,b,c;
    int y;//余数
    int s;//商
    while ( scanf("%d%d%d",&a,&b,&c)!=EOF&&a!=0&&b!=0&&c!=0 )
    {
        s = a/b;y = a%b;
        printf("%d.",s);
        for ( int i = 1;i <= c;i++ )
        {
            if ( (i<c)&&(c!=1) )
            {
                printf("%d",y*10/b);
            }
            else
            {
                if ( (y*10/b)<5 )
                    printf("%d",(y*10)/b);
                else
                    printf("%d",(y*10)/b+1);

            }
            y=y*10%b;
       }
    }
    return 0;
}

2-6

# include<cstdio>

int main(void)
{
    for ( int i = 123;i < 333;i++ )
    {
        if ((i%10)!=(i/10%10)&&(i%10)!=(i/100)&&(i/10%10)!=(i/100)
            &&((i%10)*(i/10%10)*(i/100)*(2*i%10)*(2*i/10%10)
            *(2*i/100)*(3*i%10)*(3*i/10%10)*(3*i/100)==362880))
                printf("%d %d %d\n",i,i*2,i*3);
    }


    return 0;
}