Submission #333420

#	Time	Username	Problem	Language	Result	Execution time	Memory
333420		gmyu	Secret (JOI14_secret)	C++14	0 / 100	508 ms	9964 KiB

secret

/*
ID: USACO_template
LANG: C++
PROG: USACO
*/
#include <iostream>  //cin , cout
#include <fstream>   //fin, fout
#include <stdio.h>   // scanf , pringf
#include <cstdio>
#include <algorithm> // sort , stuff
#include <stack>     // stacks
#include <queue>     // queues
#include <map>
#include <string>

#include "secret.h"

using namespace std;

typedef pair<int, int>          pii;
typedef vector<int>             vi;     /// adjlist without weight
typedef vector<pii>             vii;    /// adjlist with weight
typedef vector<pair<int,pii>>   vpip;   /// edge with weight
typedef long long               ll;

#define mp  make_pair
#define fst first
#define snd second
#define pb  push_back
#define trav(u, adj_v) for (auto& u: adj_v)

const int MOD = 1e9+7;  // 998244353;
const int MX  = 2e5+5;   //
const ll  INF = 1e18;    //

#define MAXV 100007
#define MAXE 100007

const int xdir[4] = {1,0,-1,0}, ydir[4] = {0,1,0,-1}; /// 4 directions
struct NODE {
    int x, y;
    int val;
    int visited;
    bool operator< (NODE b) const { return (x == b.x) ? (y < b.y) : (x < b.x); }
};
struct EDGE {
    int from, to;
    ll weight;
    bool operator<(EDGE other) const { return weight < other.weight; }
};

/// code from USACO examples
void setIO(string name) {
    ios_base::sync_with_stdio(0); cin.tie(0);
    freopen((name+".in").c_str(),"r",stdin);
    freopen((name+".out").c_str(),"w",stdout);
}
bool debug = false, submit = true;

/**
* RMQ use sparse table, O(N log N) memory and setip, O(1) query
* https://usaco.guide/plat/DC-SRQ
*/
int rqN;
vi x;
map<pair<int, int>, int> ans;

int rq[18][MAXV], rqmask[MAXV];      /// 18 = ceil(log2(n))


int getAns(int v1, int v2) {
    if(v1>v2) swap(v1, v2);
    pii vp = mp(v1, v2);
    if(ans.find(vp) == ans.end()) ans[vp] = Secret(v1, v2);
    return ans[vp];
}

void divi(int l, int r, int lev = 0) { // generate dat and mask
    if (l == r) return;
    int m = (l+r)/2;
    rq[lev][m] = x[m]; for(int i = m-1; i >= l; i--) rq[lev][i] = getAns(x[i], rq[lev][i+1]);
    rq[lev][m+1] = x[m+1]; for(int i = m+2; i <= r; i++) rq[lev][i] = getAns(rq[lev][i-1], x[i]);
    for(int i = m+1; i <= r; i++) rqmask[i] ^= 1<<lev;
    divi(l,m,lev+1); divi(m+1,r,lev+1);
}
int que(int l, int r) {         /// [ , ]
    if(l == r) return x[l];
    int bits = __builtin_ctz(rqmask[l]^rqmask[r]);
    return getAns(rq[bits][l], rq[bits][r]);
}

void Init(int N, int A[]) {
    rqN = N;
    for(int i = 0; i < N; i++) x.pb(A[i]);
    divi(0, N-1);
}
int Query(int L, int R) {
    que(L, R);
}

Compilation message (stderr)

secret.cpp: In function 'int Query(int, int)':
secret.cpp:99:1: warning: no return statement in function returning non-void [-Wreturn-type]
   99 | }
      | ^
secret.cpp: In function 'void setIO(std::string)':
secret.cpp:55:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   55 |     freopen((name+".in").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
secret.cpp:56:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   56 |     freopen((name+".out").c_str(),"w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100