hdu 2561~2566 水题集合

2561：

#include <iostream>
#include <cstring>
using namespace std;

const int N = 10;
int num[N];

int main()
{
    int t;
    cin >> t;
    while ( t-- )
    {
        int n;
        cin >> n;
        for ( int i = 0; i < n; i++ )
        {
            cin >> num[i];
        }
        int tmp = 0;
        for ( int i = 1; i < n; i++ )
        {
            if ( num[tmp] > num[i] ) tmp = i;
        }
        num[tmp] = 100;
        tmp = 0;
        for ( int i = 1; i < n; i++ )
        {
            if ( num[tmp] > num[i] ) tmp = i;
        }
        cout << num[tmp] << endl;
    }
    return 0;
}

2562：

#include <iostream>
#include <cstring>
using namespace std;

const int N = 51;
char num[N];

int main()
{
    int t;
    cin >> t;
    while ( t-- )
    {
        cin >> num;
        int len = strlen(num);
        for ( int i = 0; i < len - 1; i += 2 )
        {
            swap( num[i], num[i + 1] );
        }
        cout << num << endl;
    }
    return 0;
}

2563：

 递推咯。

#include <iostream>
using namespace std;

const int N = 21;
int f[N];

void get()
{
    f[0] = 1;
    f[1] = 3;
    for ( int i = 2; i < N; i++ )
    {
        f[i] = f[i - 1] * 2 + f[i - 2];
    }
}

int main ()
{
    get();
    int t;
    cin >> t;
    while ( t-- )
    {
        int n;
        cin >> n;
        cout << f[n] << endl;
    }
    return 0;
}

2564：

#include <cstring>
#include <cstdio>
#include <cctype>
using namespace std;

const int N = 101;
char word[N];

int main ()
{
    int t;
    scanf("%d", &t);
    getchar();
    while ( t-- )
    {
        gets(word);
        int len = strlen(word);
        for ( int i = 0; i < len; i++ )
        {
            if ( isalpha(word[i]) )
            {
                char ch = toupper(word[i]);
                printf("%c", ch);
                do
                {
                    i++;
                } while ( isalpha(word[i]) );
            }
        }
        puts("");
    }
    return 0;
}

2565：

这个题的格式真是坑...

#include <cstring>
#include <cstdio>
#include <cctype>
using namespace std;

const int N = 100;
char grid[N][N];

void make( int n )
{
    for ( int i = 0; i < n; i++ )
        for ( int j = 0; j < n; j++ )
            grid[i][j] = ' ';
    int k = 0;
    while ( k < n )
    {
        grid[k][k] = 'X';
        k++;
    }
    k = n - 1;
    while ( k > -1 )
    {
        grid[k][n - 1 - k] = 'X';
        k--;
    }
}

void out( int n )
{
    for ( int i = 0; i < n; i++ )
    {
        int cnt = 0;
        for ( int j = 0; j < n; j++ )
        {
            printf("%c", grid[i][j]);
            if ( grid[i][j] == 'X' )
            {
                if ( i == n / 2 )
                {
                    break;
                }
                cnt++;
                if ( cnt == 2 ) break;
            }
        }
        puts("");
    }
    puts("");
}

int main ()
{
    int t;
    scanf("%d", &t);
    while ( t-- )
    {
        int n;
        scanf("%d", &n);
        make(n);
        out(n);
    }
    return 0;
} 

2566：

没有数据范围的流氓题，果断枚举水之。

#include <iostream>
using namespace std;

int main ()
{
    int t;
    cin >> t;
    while ( t-- )
    {
        int n, m;
        cin >> n >> m;
        int cnt = 0;
        for ( int i = 0; i <= n; i++ )
        {
            for ( int j = 0; j <= n - i; j++ )
            {
                int k = n - i - j;
                if ( i + j * 2 + k * 5 == m ) cnt++;
            }
        }
        cout << cnt << endl;
    }
    return 0;
}