Submission #835110

#	Time	Username	Problem	Language	Result	Execution time	Memory
835110		TS_2392	Sailing Race (CEOI12_race)	C++14	100 / 100	2330 ms	5264 KiB

race

#include <bits/stdc++.h>
using namespace std;

#define fileIO(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);}
#define SPEED {ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0);}
template<class T1, class T2> bool minimize(T1 &a, T2 b){return a > b ? a = b, true : false;}
template<class T1, class T2> bool maximize(T1 &a, T2 b){return a < b ? a = b, true : false;}

const int N = 505;
int n, type, res, res_vtx, nxt[N], prv[N];
int adj[N][N], dp[N][N][2], f[N][N][2];
int main(){
   	SPEED; fileIO("text");
    cin >> n >> type;
    for(int u = 1, v; u <= n; ++u){
        cin >> v;
		while(v > 0){
			adj[u][v] = 1;
			cin >> v;
		}
        nxt[u] = u + 1; prv[u] = u - 1;
    }
    nxt[n] = 1; prv[1] = n;
    for(int len = 2; len <= n; ++len){
        for(int i = 1; i <= n; ++i){
            int j = i + len - 1;
            if(j > n) j -= n;
            //compute dp[i][j][0]
            if(adj[i][j]) dp[i][j][0] = 1 + dp[j][nxt[i]][1];
            for(int k = i; k != j; k = nxt[k]) if(adj[i][k]){
                maximize(dp[i][j][0], max(dp[k][j][0], dp[k][nxt[i]][1]) + 1);
            }
            //compute dp[j][i][1]
            if(adj[j][i]) dp[j][i][1] = 1 + dp[i][prv[j]][0];
            for(int k = j; k != i; k = prv[k]) if(adj[j][k]){
                maximize(dp[j][i][1], max(dp[k][prv[j]][0], dp[k][i][1]) + 1);
            }

            if(maximize(res, dp[i][j][0])) res_vtx = i;
            if(maximize(res, dp[j][i][1])) res_vtx = j;
        }
    }
    if(type){
        for(int len = 2; len <= n; ++len){
            for(int i = 1; i <= n; ++i){
                int j = i + len - 1;
                if(j > n) j -= n;
                //compute f[i][j][0];
                if(adj[i][j]) f[i][j][0] = 1;
                for(int k = i; k != j; k = nxt[k]) if(adj[i][k] && f[k][j][0]){
                    maximize(f[i][j][0], f[k][j][0] + 1);
                }
                //compute f[j][i][1]
                if(adj[j][i]) f[j][i][1] = 1;
                for(int k = j; k != i; k = prv[k]) if(adj[j][k] && f[k][i][1]){
                    maximize(f[j][i][1], f[k][i][1] + 1);
                }
            }
        }
        for(int a = 1; a <= n; ++a){
            for(int b = nxt[a]; b != a; b = nxt[b]){
                for(int c = nxt[a], ma = -1; c != b; c = nxt[c]){
                    if(adj[a][c] && ma >= 0 && f[c][b][0]){
                        if(maximize(res, f[c][b][0] + 2 + ma)) res_vtx = a;
                    }
                    if(adj[b][c]) maximize(ma, dp[c][nxt[a]][1]);
                }
                for(int c = prv[a], ma = -1; c != b; c = prv[c]){
                    if(adj[a][c] && ma >= 0 && f[c][b][1]){
                        if(maximize(res, f[c][b][1] + 2 + ma)) res_vtx = a;
                    }
                    if(adj[b][c]) maximize(ma, dp[c][prv[a]][0]);
                }
            }
        }
        for(int c = 1; c <= n; ++c){
            for(int d = nxt[c]; d != c; d = nxt[d]){
                for(int a = nxt[d], ma = -1; a != c; a = nxt[a]){
                    if(adj[a][d] && ma >= 0){
                        if(maximize(res, dp[c][prv[d]][0] + 2 + ma)) res_vtx = a;
                    }
                    if(adj[a][c] && f[d][a][0]) maximize(ma, f[d][a][0]);
                }
                for(int a = prv[d], ma = -1; a != c; a = prv[a]){
                    if(adj[a][d] && ma >= 0){
                        if(maximize(res, dp[c][nxt[d]][1] + 2 + ma)) res_vtx = a;
                    }
                    if(adj[a][c] && f[d][a][1]) maximize(ma, f[d][a][1]);
                }
            }
        }
    }
    cout << res << '\n' << res_vtx;
    return 0;
}

Compilation message (stderr)

race.cpp: In function 'int main()':
race.cpp:4:57: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    4 | #define fileIO(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);}
      |                                                  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
race.cpp:13:12: note: in expansion of macro 'fileIO'
   13 |     SPEED; fileIO("text");
      |            ^~~~~~
race.cpp:4:90: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    4 | #define fileIO(name) if(fopen(name".inp", "r")) {freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);}
      |                                                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
race.cpp:13:12: note: in expansion of macro 'fileIO'
   13 |     SPEED; fileIO("text");
      |            ^~~~~~

• Subtask 1: 100 / 100