Submission #1771324

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll=long long;
using vi=vector<int>;
using pii=pair<int,int>;
#define ALL(c) begin(c),end(c)
#define RALL(c) rbegin(c),rend(c)
#define ITR(i,b,e) for(auto i=(b);i!=(e);++i)
#define FORE(x,c) for(auto &x:c)
#define REPF(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define REP(i,n) REPF(i,0,n)
#define REPR(i,n) for(int i=(int)(n);i>=0;--i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c,x) (c.find(x)!=end(c))
#define OUTOFRANGE(y,x,h,w) (y<0||x<0||y>=h||x>=w)
#define dump(...)
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template<class T> ostream& operator << (ostream &os,const vector<T> &v) {
    ITR(i,begin(v),end(v)) os<<*i<<(i==end(v)-1?"":"\n"); return os; }
template<class T> istream& operator >> (istream &is,vector<T> &v) {
    ITR(i,begin(v),end(v)) is>>*i; return is; }
template<class T> istream& operator >> (istream &is, pair<T,T> &p) {
    is>>p.first>>p.second; return is; }
template <class T> bool chmax(T &a,const T &b) {if(a<b) {a=b;return 1;} return 0;}
template <class T> bool chmin(T &a,const T &b) {if(b<a) {a=b;return 1;} return 0;}
template <class T> using heap = priority_queue<T,vector<T>,greater<T>>;
struct before_main_function {
    before_main_function() {
        #ifdef int
            #undef INF
            #define INF INFLL
            #define stoi stoll
        #endif
        cin.tie(0);ios::sync_with_stdio(false);
        cout<<setprecision(15)<<fixed;
        #define endl "\n"
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

string K;
int dp[20][2][2];
int dfs(int i,int ng,int le) {
    if(dp[i][ng][le]!=INF) return dp[i][ng][le];
    if(i==SZ(K)) return ng;
    int ret=0;
    int d=K[i]-'0';
    if(ng) {
        if(le) {
            ret+=dfs(i+1,1,1)*10;
        } else {
            ret+=dfs(i+1,1,0); // d
            ret+=dfs(i+1,1,1)*d;
        }
    } else {
        if(le) {
            ret+=dfs(i+1,1,1)*2;  // 4, 9
            ret+=dfs(i+1,0,1)*8;  // other
        } else {
            ret+=dfs(i+1,(d==4||d==9),0); // d
            REP(j,d) {
                if(j==4||j==9) {
                    ret+=dfs(i+1,1,1);
                } else {
                    ret+=dfs(i+1,0,1);
                }
            }
        }
    }
    return dp[i][ng][le]=ret;
}
signed main() {
    int A,B;
    cin>>A>>B;
    REP(i,20) REP(j,2) REP(k,2) dp[i][j][k]=INF;
    K=to_string(A-1);
    int a=dfs(0,0,0);
    REP(i,20) REP(j,2) REP(k,2) dp[i][j][k]=INF;
    K=to_string(B);
    int b=dfs(0,0,0);
    cout<<b-a<<endl;
    return 0;
}

Submission Info

Judge Result