【hihocoder1251】Today is a rainy day

#include<bits/stdc++.h>
const int N=120;
const int M=5e4+5;
const int inf=0x3f3f3f3f;
using namespace std;
char s1
,s2
;
int c[6],f[6][6],dis[M];
inline int Index(int *a){
int ans=0;
for(int i=0;i<6;i++)ans=ans*6+a[i];
return ans;
}
inline void hs(int x,int *a){
for(int i=5;i>=0;i--)a[i]=x%6,x/=6;
}
inline void bfs(){
memset(dis,127,sizeof(dis));int b[6];
for(int i=0;i<6;i++)b[i]=i;
int x=Index(b);dis[x]=0;
static queue<int> q;q.push(x);
while(!q.empty()){
int u=q.front();q.pop();
hs(u,b);
for(int i=0;i<6;i++)for(int j=0;j<6;j++){
int t[6];memcpy(t,b,sizeof(t));
for(int k=0;k<6;k++)if(t[k]==i)t[k]=j;
int v=Index(t);
if(dis[v]>dis[u]+1)dis[v]=dis[u]+1,q.push(v);
}
}
}
int main(){
freopen("ff.in","r",stdin);
freopen("dick.out","w",stdout);
bfs();
while(~scanf("%s%s",s1,s2)){
int len=strlen(s1);
memset(c,0,sizeof(c));memset(f,0,sizeof(f));
for(int i=0;i<len;i++){
int x=s2[i]-'1',y=s1[i]-'1';c[x]++;f[x][y]++;
}
int ans=inf,b[6];
for(int i=0;i<M;i++){
hs(i,b);int tmp=dis[i];
for(int j=0;j<6;j++)tmp+=c[j]-f[j][b[j]];
ans=min(ans,tmp);
}
printf("%d\n",ans);
}
}