Submission #759035

#	Time	Username	Problem	Language	Result	Execution time	Memory
759035		YassineBenYounes	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	169 ms	19664 KiB

jumps

#include<bits/stdc++.h>
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef double db;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define pbds tree<pair<int, int>, null_type, less<pair<int, int>>,rb_tree_tag, tree_order_statistics_node_update>
using namespace __gnu_pbds;
ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (PGCD)
ll lcm(ll a , ll b) {return (a * b) / gcd(a , b);} // least common multiple (PPCM)
int dx[8] = {1, 0, 0, -1, 1, 1, -1, -1};
int dy[8] = {0, 1, -1, 0, 1, -1, -1, 1};
#define endl "\n"
#define ss second
#define ff first
#define all(x) (x).begin() , (x).end()
#define pb push_back
#define vi vector<int>
#define vii vector<pair<int,int>>
#define vl vector<ll>
#define vll vector<pair<ll,ll>>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pdd  pair<double,double>
#define vdd  vector<pdd>
#define speed ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
////////////////////Only Clear Code//////////////////////////

void usaco_problem(){
    freopen("milkvisits.in", "r", stdin);
    freopen("milkvisits.out", "w", stdout);
}

void init(){
    #ifndef ONLINE_JUDGE
 
freopen("input.txt", "r", stdin);
 
freopen("output.txt", "w", stdout);
 
#endif // ONLINE_JUDGE
}

const int mx = 2e5+5;
const int LOG = 20;
const ll inf = 1e15;
const ll mod = 1e9+7;

int n;

int after[mx], before[mx], arr[mx];

int nxt[mx][LOG+5];

void preprocess(){
    stack<int> st;
    for(int i = 0; i < n;i++){
        while(!st.empty() && arr[st.top()] < arr[i]){
            st.pop();
        }
        if(st.empty())before[i] = -1;
        else before[i] = st.top();
        st.push(i);
    }
    while(!st.empty())st.pop();
    for(int i = n-1; i >= 0;i--){
        while(!st.empty() && arr[st.top()] < arr[i]){
            st.pop();
        }
        if(st.empty())after[i] = -1;
        else after[i] = st.top();
        st.push(i);
    }
    for(int i = 0; i < n;i++){
        if(before[i] == -1 && after[i] == -1)nxt[i][0] = i;
        else if(before[i] == -1)nxt[i][0] = after[i];
        else if(after[i] == -1)nxt[i][0] = before[i];
        else nxt[i][0] = (arr[before[i]] > arr[after[i]] ? before[i] : after[i]);
    }
    for(int j = 1;j <= LOG;j++){
        for(int i = 0; i < n;i++){
            nxt[i][j] = nxt[nxt[i][j-1]][j-1];
        }
    }
}

void init(int N, vi h){
    n = N;
    for(int i = 0; i < n;i++){
        arr[i] = h[i]; 
    }
    preprocess();
}

int minimum_jumps(int a, int b, int c, int d){
    int node = a;
    int dis = 0;
    for(int j = LOG;j >= 0;j--){
        int nd = nxt[a][j];
        if(arr[nd] < arr[c]){
            dis += (1 << j);
            node = nd;
        }
    }
    if(before[node] == c || after[node] == c){
        return dis+1;
    }
    return -1;
}


/*
void run_case(){
    init(7, {3, 2, 1, 6, 4, 5, 7});
    cout << minimum_jumps(4, 4, 6, 6) << endl;
}

int main(){
    init();
    speed;
    int t;
    //cin >> t;
    t = 1;
    while(t--){
        run_case();
    }
}*/

/*
    NEVER GIVE UP!
    DOING SMTHNG IS BETTER THAN DOING NTHNG!!!
    Your Guide when stuck:
    - Continue keyword only after reading the whole input
    - Don't use memset with testcases
    - Check for corner cases(n=1, n=0)
    - Check where you declare n(Be careful of declaring it globally and in main)
*/

Compilation message (stderr)

jumps.cpp: In function 'void usaco_problem()':
jumps.cpp:33:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     freopen("milkvisits.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
jumps.cpp:34:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     freopen("milkvisits.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
jumps.cpp: In function 'void init()':
jumps.cpp:40:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 | freopen("input.txt", "r", stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
jumps.cpp:42:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 | freopen("output.txt", "w", stdout);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 12
• Subtask 5: 0 / 23
• Subtask 6: 0 / 21
• Subtask 7: 0 / 19