Sonya and Matrix Beauty Codeforces - 1080E

https://codeforces.com/contest/1080/problem/E

比赛时候一个多小时码不出来。。。

来看遇到的困难：

1.没有能用的随机unsignedlonglong函数

来一个可以A题的：

ull splitmix64(ull x) {
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> )) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> )) * 0x94d049bb133111eb;
    return x ^ (x >> );
}
ull rd()
{
    static ull x=splitmix64(chrono::steady_clock::now().time_since_epoch().count());
    return splitmix64(x=x*6364136223846793005ull+1442695040888963407ull);
}

2.不会马拉车

以后学。。以下代码的马拉车(calc函数)是网上找的

 #include<cstdio>
 #include<algorithm>
 #include<cstring>
 #include<vector>
 #include<chrono>
 #include<cstdlib>
 using namespace std;
 #define fi first
 #define se second
 #define mp make_pair
 #define pb push_back
 typedef long long ll;
 typedef unsigned long long ull;
 typedef pair<int,int> pii;

 ull cpy[];
 int rad[];

 ull splitmix64(ull x) {
     x += 0x9e3779b97f4a7c15;
     x = (x ^ (x >> )) * 0xbf58476d1ce4e5b9;
     x = (x ^ (x >> )) * 0x94d049bb133111eb;
     return x ^ (x >> );
 }
 ull rd()
 {
     static ull x=splitmix64(chrono::steady_clock::now().time_since_epoch().count());
     return splitmix64(x=x*6364136223846793005ull+1442695040888963407ull);
 }

 void manacher(ull str[], int rad[], int len) {
     for (int i=,j=,k; i < len; i+=k,j-=k) {
         while (str[i-j-] == str[i+j+]) ++j;
         rad[i] = j;
         for (k=; k<=j && rad[i-k]!=rad[i]-k; ++k) {
             rad[i+k] = min(rad[i-k], rad[i]-k);
         }
     }
 }

 ll calc(const ull *seq,int len)
 {
     //for(int i=0;i<len;++i)
     //    printf("1t%llu\n",seq[i]);
     ull t1,t2,t3;
     while()
     {
         t1=rd();t2=rd();t3=rd();
         if(t1==t2||t1==t3||t2==t3)    continue;
         for(int i=;i<len;++i)
             if(t1==seq[i]||t2==seq[i]||t3==seq[i])
                 continue;
         break;
     }
     cpy[] = t1, cpy[] = t2;
     for (int i=,j=; j < len; i+=,++j) {
         cpy[i] = seq[j];
         cpy[i+] = t2;
     }
     len = len*+;
     cpy[len-] = t3;
     manacher(cpy, rad, len);
     ll ret = ;
     for (int i = ; i < len-; ++i) {
         ret += (rad[i]+) / ;
     }
     //printf("2t%lld\n",ret);
     return ret;
 }

 ull bs,bss[]={,,,,,};
 ull pwx[];
 ull st[];int tp;
 struct CharSet
 {
     int num[],odd;
     ull hs;
     void add(int c)
     {
         ++num[c];
         odd^=(<<c);
         hs+=pwx[c];
     }
     void del(int c)
     {
         --num[c];
         odd^=(<<c);
         hs-=pwx[c];
     }
     void clear()
     {
         memset(num,,sizeof(num));
         odd=;
         hs=;
     }
 }cs[];
 ll ans;
 bool ok[];
 int n,m;
 int to[];
 char s[][];
 int main()
 {
     int i,j,l,r;
     bs=bss[rd()%];
     //printf("1t%llu\n",bs);
     pwx[]=;
     for(i=;i<=;++i)
         pwx[i]=pwx[i-]*bs;
     //n=250;m=250;
     scanf("%d%d",&n,&m);
     for(i=;i<=n;++i)
     {
         scanf("%s",s[i]+);
         //for(j=1;j<=m;++j)
         //    s[i][j]=rand()%3+'a';
     }
     for(l=;l<=m;++l)
     {
         for(i=;i<=n;++i)
             cs[i].clear();
         for(r=l;r<=m;++r)
         {
             for(i=;i<=n;++i)
                 cs[i].add(s[i][r]-'a');
             if((r-l+)&)
             {
                 for(i=;i<=n;++i)
                 {
                     to[i]=__builtin_ffs(cs[i].odd)-;
                     cs[i].del(to[i]);
                 }
             }
             for(i=;i<=n;++i)
                 ok[i]=!cs[i].odd;
             if((r-l+)&)
             {
                 for(i=;i<=n;++i)
                     cs[i].add(to[i]);
             }
             //printf("3t%d %d\n",l,r);
             //for(i=1;i<=n;++i)
             //    printf("4t%llu\n",cs[i].hs);
             for(i=;i<=n;++i)
                 if(ok[i])
                 {
                     tp=;
                     j=i;st[++tp]=cs[i].hs;
                     while(j+<=n&&ok[j+])
                     {
                         ++j;
                         st[++tp]=cs[j].hs;
                     }
                     ans+=calc(st+,tp);
                     i=j;
                 }
                 //printf("5t%lld\n",ans);
         }
     }
     printf("%lld\n",ans);
     return ;
 }