2014 UESTC 暑前集训队内赛(2) 部分解题报告

B.Cuckoo for Hashing

模拟题。

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <string>
#include <vector>
using namespace std;
#define N 50007

int a[],b[];

int main()
{
    int n1,n2,m,i;
    int x,fx,tx;
    int tmp,tmp2;
    int cs = ;
    while(scanf("%d%d%d",&n1,&n2,&m)!=EOF && (n1||n2||m))
    {
        memset(a,-,sizeof(a));
        memset(b,-,sizeof(b));
        while(m--)
        {
            scanf("%d",&x);
            fx = x%n1;
            tx = ;
            if(a[fx] == -)
            {
                a[fx] = x;
                continue;
            }
            tmp2 = x;
            while(a[fx] != -)
            {
                tmp = a[fx];
                a[fx] = tmp2;
                tx = tmp%n2;
                if(b[tx] != -)
                {
                    tmp2 = b[tx];
                    b[tx] = tmp;
                    fx = tmp2%n1;
                }
                else
                {
                    b[tx] = tmp;
                    break;
                }
            }
            if(a[fx] == -)
                a[fx] = tmp2;
        }
        printf("Case %d:\n",cs++);
        int flag = ;
        //printf("Table 1\n");
        for(i=;i<n1;i++)
        {
            if(a[i] != -)
            {
                flag = ;
                break;
            }
        }
        if(flag)
        {
            printf("Table 1\n");
            for(i=;i<n1;i++)
            {
                if(a[i] != -)
                    printf("%d:%d\n",i,a[i]);
            }
        }
        flag = ;
        for(i=;i<n2;i++)
        {
            if(b[i] != -)
            {
                flag = ;
                break;
            }
        }
        if(flag)
        {
            printf("Table 2\n");
            for(i=;i<n2;i++)
            {
                if(b[i] != -)
                    printf("%d:%d\n",i,b[i]);
            }
        }
    }
    return ;
}

C.Playing Fair with Cryptography

模拟题，注意细节就好。遇到J的情况要及时跳走。

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <string>
using namespace std;
#define N 50007

char mp[][];
char key[],text[];
int vis[];

string RUN(string ss)
{
    int i,j;
    int a,b;
    int c,d;
    string ans = "";
    for(i=;i<;i++)
    {
        for(j=;j<;j++)
        {
            if(mp[i][j] == ss[])
                a = i,b = j;
            if(mp[i][j] == ss[])
                c = i,d = j;
        }
    }
    if(a == c)
    {
        int newb = (b+)%;
        ans += mp[a][newb];
        int newd = (d+)%;
        ans += mp[a][newd];
        return ans;
    }
    else if(b == d)
    {
        int newa = (a+)%;
        ans += mp[newa][b];
        int newc = (c+)%;
        ans += mp[newc][b];
        return ans;
    }
    else
    {
        int newb = d;
        int newd = b;
        ans += mp[a][newb];
        ans += mp[c][newd];
        return ans;
    }
}

int main()
{
    int t,i,cs = ,j,k;
    int x,y;
    scanf("%d",&t);
    getchar();
    while(t--)
    {
        gets(key);
        gets(text);
        int len1 = strlen(text);
        int len2 = strlen(key);
        memset(vis,,sizeof(vis));
        k = ;
        for(i=;i<len2;i++)
        {
            char ch = key[i];
            if((ch >= 'A' && ch <= 'Z'))
            {
                if(vis[ch-'A'])
                    continue;
                vis[ch-'A'] = ;
                mp[k/][k%] = ch;
                k++;
            }
            else if(ch >= 'a' && ch <= 'z')
            {
                ch -= ;
                if(vis[ch-'A'])
                    continue;
                vis[ch-'A'] = ;
                mp[k/][k%] = ch;
                k++;
            }
        }
        for(char chh = 'A';chh<='Z';chh++)
        {
            if(chh == 'J')
                continue;
            if(!vis[chh-'A'])
            {
                mp[k/][k%] = chh;
                k++;
            }
        }
        //alpha table established
        char ss[];
        k = ;
        for(i=;i<len1;i++)
        {
            if(text[i] >= 'A' && text[i] <='Z')
                ss[k++] = text[i];
            else if(text[i] >= 'a' && text[i] <= 'z')
                ss[k++] = text[i]-;
        }
        ss[k] = '\0';
        printf("Case %d: ",cs++);
        int nowch = ;
        char nowchar;
        string cy = "";
        for(i=;i<k-;i+=)
        {
            if(nowch == )
                nowch++,nowch%=;
            if(ss[i] == ss[i+])
            {
                if(ss[i] == (nowch%) + 'A')
                {
                    nowchar = (++nowch)% + 'A';
                    if(nowchar == 'J')
                        nowch++,nowchar = 'K';
                }
                nowchar = (nowch%) + 'A';
                if(nowchar == 'J')
                        nowch++,nowchar = 'K';
                cy = "";
                cy += ss[i];
                cy += nowchar;
                cout<<RUN(cy);
                nowch = (nowch+)%;
                i -= ;
            }
            else
            {
                cy = "";
                cy += ss[i];
                cy += ss[i+];
                cout<<RUN(cy);
            }
        }
        if(i == k-)
        {
            nowchar = nowch% + 'A';
            if(ss[i] == nowchar)
            {
                nowchar = (++nowch)% + 'A';
            }
            if(nowchar == 'J')
                nowch++,nowchar = 'K';
            cy = "";
            cy += ss[i];
            cy += nowchar;
            cout<<RUN(cy);
        }
        cout<<endl;
    }
    return ;
}

H.The Urge to Merge

DP。借鉴标程代码。

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <string>
#define Mod 1000000007
using namespace std;
#define N 50007

int mp[][];
ll dp[][];

ll Max(ll a,ll b,ll c,ll d)
{
    return max(max(max(a,b),c),d);
}

int main()
{
    int cs = ,n;
    int i,j,k;
    while(scanf("%d",&n)!=EOF && n)
    {
        for(i=;i<;i++)
            for(j=;j<=n;j++)
                scanf("%d",&mp[i][j]);
        //memset(dp,0,sizeof(dp));
        for(i=;i<;i++)
            dp[i][] = dp[i][] = ;
        dp[][] = mp[][]*mp[][];
        dp[][] = mp[][]*mp[][];
        ll k1 = Max(dp[][],dp[][],,);
        ll k2 = ;
        ll s1,s2,s3,s4,s5;

        for(j=;j<=n;j++)
        {
            s1 = mp[][j-]*mp[][j];
            s2 = mp[][j-]*mp[][j];
            s3 = mp[][j-]*mp[][j];
            s4 = mp[][j]*mp[][j];
            s5 = mp[][j]*mp[][j];

            dp[][j] = Max(k2,dp[][j-],dp[][j-],dp[][j-])+s1;  //第一种组合
            dp[][j] = Max(k2,dp[][j-],dp[][j-],dp[][j-])+s2;  //第二种组合
            dp[][j] = Max(k2,dp[][j-],dp[][j-],dp[][j-])+s3;  //第三种组合

            dp[][j] = Max(k2+s1+s2,dp[][j-]+s1+s2,k1+s4,);
            dp[][j] = Max(k2,dp[][j-],,)+s1+s3;
            dp[][j] = Max(k2+s2+s3,dp[][j-]+s2+s3,k1+s5,);
            dp[][j] = Max(k2+s1+s2+s3,dp[][j]+s5,dp[][j]+s4,);
            k2 = k1;
            for(i=;i<;i++)
                k1 = max(k1,dp[i][j]);
        }
        ll ans = -Mod;
        for(i=;i<;i++)
            ans = max(ans,dp[i][n]);
        printf("Case %d: %d\n",cs++,ans);
    }
    return ;
}

（没做出来的以后持续更新）