2017-2018 ACM-ICPC, NEERC, Northern Subregional Contest C

2017-2018 ACM-ICPC, NEERC, Northern Subregional Contest

C

好久前做的，忘记了，，， 好像是个图论瞎搞题。。

#include<bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
#define rep(i,a,b) for (int i=a; i<=b; ++i)
#define per(i,b,a) for (int i=b; i>=a; --i)
#define mes(a,b)  memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f
#define MP make_pair
#define PB push_back
#define fi  first
#define se  second
typedef long long ll;
const int N = 1000005;

char s[N], vow[10] = { 'a', 'e', 'i', 'o', 'u', 'w', 'y' };
int len, con[21], num[28][28];
vector< int > G[28];
bool vis[28], vis1[28];
bool is(char x)  {
    rep(i,0,6)
        if(x==vow[i])
            return false;
    return true;
}
int dfs(int u)
{
    vis1[u] = true;
    int ans = 0;
    for(auto to : G[u])
    {
        if(vis[u] ^ vis[to] == 1) ans += num[u][to];
        if(!vis1[to])  ans += dfs(to);

    }
    return ans;
}
int main()
{
    freopen("consonant.in","r",stdin); freopen("consonant.out","w",stdout);
    scanf("%s", s+1);
    len = strlen(s+1);
    rep(i,1,len-1)
    {
        if(is(s[i]) && is(s[i+1])) {
            int ch1=s[i]-'a', ch2=s[i+1]-'a';
            if(num[ch1][ch2]==0) G[ch1].PB(ch2);
            if(num[ch2][ch1]==0) G[ch2].PB(ch1);
            ++num[ch1][ch2];
            ++num[ch2][ch1];
        }
    }
    int cnt = 0;
    rep(i,0,25)
        if(is('a'+i))
            con[cnt++] = i;
    int ans = 0, mx = -1;
    rep(i,0,(1<<19)-1)
    {
        mes(vis, false);
        rep(j,0,18) {
            if((i>>j)&1) vis[con[j]]=true;
        }
        mes(vis1, false);
        int ans1 = 0;
        rep(j,0,18) {
            int ch = con[j];
            if(!vis1[ch]) ans1 += dfs(ch)/2;
        }
        if(ans < ans1) ans=ans1, mx=i;
    }
    mes(vis, false);
    if(mx != -1) {
        rep(j,0,18) {
            if((mx>>j)&1) vis[con[j]]=true;
        }
    }
    rep(i,1,len) putchar(vis[s[i]-'a'] ? (s[i]-32) : s[i]);
    puts("");

    return 0;
}