暴力模拟——cf988E

很简单的题，就是模拟一下

#include<bits/stdc++.h>
using namespace std;
#define ll long long
ll n,a[100],len;

int f(int x,int y){
    ll b[100],flag=0,res=0;
    memcpy(b,a,sizeof a);
    
    int pos;
    for(int i=1;i<=len;i++)
        if(b[i]==y){
            pos=i;flag=1;break;
        }
    if(flag==0)return 0x3f3f3f3f;
    flag=0;
    for(int i=pos;i>1;i--)
        swap(b[i],b[i-1]),res++;
    
    for(int i=2;i<=len;i++)
        if(b[i]==x){
            pos=i;flag=1;break;
        }
    if(flag==0)return 0x3f3f3f3f;
    flag=0;
    for(int i=pos;i>2;i--)
        swap(b[i],b[i-1]),res++;
    
    if(b[len]==0){
        for(int i=len-1;i>=3;i--)
            if(b[i]!=0){
                pos=i;flag=1;break;
            }
        if(flag==0)return 0x3f3f3f3f;
        for(int i=len;i>pos;i--)
            swap(b[i],b[i-1]),res++;
    }
    
    return res;
}

int main(){
    cin>>n;
    while(n){
        a[++len]=n%10;
        n/=10;
    }
    int ans=0x3f3f3f3f;
    ans=min(ans,f(0,0));
    ans=min(ans,f(2,5));
    ans=min(ans,f(5,0));
    ans=min(ans,f(7,5));
    if(ans!=0x3f3f3f3f)
        cout<<ans;
    else cout<<-1;
}