Submission #484350

#	Time	Username	Problem	Language	Result	Execution time	Memory
484350		MohamedFaresNebili	Cop and Robber (BOI14_coprobber)	C++14	30 / 100	52 ms	1756 KiB

coprobber

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#pragma GCC optimize ("Ofast")
#pragma GCC target ("avx2")
#include "coprobber.h"

        using namespace std;
        using namespace __gnu_pbds;

        using ll  = long long;
        using ld  = long double;
        using ii  = pair<ll, ll>;
        using ull = unsigned long long;

        using vl  = vector<long long>;

        #define mp make_pair
        #define pb push_back
        #define pp pop_back
        #define ff first
        #define ss second
        #define lb lower_bound
        #define ub upper_bound
        #define all(x) (x).begin() , (x).end()
        #define vi vector<int>

        const int N = 2*100005;
        const long long MOD = 1000000007;
        const long double EPS = 0.000000001;
        const double PI = 3.14159265358979323846;
        const long long INF = 10000000000000000;
        const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0};
        int dist(int x, int y, int a, int b) { return abs(x-a)+abs(y-b); }

        long long gcd(int a, int b) { return (b==0?a:gcd(b, a%b)); }
        long long lcm(int a, int b) { return  a*(b/gcd(a, b)); }
        long long fact(int a) { return (a==1?1:a*fact(a-1)); }

        template<class T> using Tree = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;

        #define MAX_N 500

        vector<int>adj[MAX_N];

        int police = 0;
        int r, c; bool grid = 0;
        bool check(int n) {
            bool ok = true; int curr = 0; int l;
            for(l = 0; l < n && curr < 2; l++) {
                curr += ((int)adj[l].size() == 2);
                ok &= ((int)adj[0].size() == 2);
                if(l&&curr<2) ok &= ((int)adj[l].size() == 3);
            }
            ok &= (curr == 2);
            return ok;
        }

        int start(int N, bool A[MAX_N][MAX_N])
        {
            for(int l = 0; l < N; l++) {
                for(int i=0; i < N; i++) {
                    if(A[l][i]) adj[l].pb(i);
                }
            }
            grid = check(N);
            if(grid) c = adj[0][1], r = N/c;
            return 0;
        }

        bool dfs(int v, int p, int dest) {
            if(v == dest) return 1;
            for(auto u:adj[v]) {
                if(u == p) continue;
                if(dfs(u, v, dest)) return 1;
            }
            return 0;
        }

        int nextMove(int R)
        {
            if(grid) {
                int r1 = police / c, r2 = R / c;
                int c1 = police % c, c2 = R % c;
                int a = abs(r1 - r2), b = abs(c1 - c2);
                if(a < b) {
                    int curr = 1e9, xx, yy;
                    for(int l = 0; l < 2; l++) {
                        int x = r1 + nx[l], y = c1 + ny[l];
                        int d = dist(x, y, r2, c1);
                        if(d < curr) xx = x, yy = y, curr = d;
                    }
                    return police = xx * c + yy;
                }
                else if(a > b) {
                    int curr = 1e9, xx, yy;
                    for(int l = 2; l < 4; l++) {
                        int x = r1 + nx[l], y = c1 + ny[l];
                        int d = dist(x, y, r2, c1);
                        if(d < curr) xx = x, yy = y, curr = d;
                    }
                    return police = xx * c + yy;
                }
                else if(a == b) return police;
            }
            for(auto u:adj[police]) {
                if(u==R||dfs(u, police, R)) {
                    return police = u;
                }
            }
            return -1;
        }

Compilation message (stderr)

coprobber.cpp: In function 'int nextMove(int)':
coprobber.cpp:101:44: warning: 'yy' may be used uninitialized in this function [-Wmaybe-uninitialized]
  101 |                     return police = xx * c + yy;
      |                                     ~~~~~~~^~~~
coprobber.cpp:101:40: warning: 'xx' may be used uninitialized in this function [-Wmaybe-uninitialized]
  101 |                     return police = xx * c + yy;
      |                                     ~~~^~~
coprobber.cpp:92:44: warning: 'yy' may be used uninitialized in this function [-Wmaybe-uninitialized]
   92 |                     return police = xx * c + yy;
      |                                     ~~~~~~~^~~~
coprobber.cpp:92:40: warning: 'xx' may be used uninitialized in this function [-Wmaybe-uninitialized]
   92 |                     return police = xx * c + yy;
      |                                     ~~~^~~

• Subtask 1: 16 / 16
• Subtask 2: 14 / 14
• Subtask 3: 0 / 30
• Subtask 4: 0 / 40