Submission #46118

#	Time	Username	Problem	Language	Result	Execution time	Memory
46118		RockyB	Robots (APIO13_robots)	C++17	100 / 100	809 ms	102952 KiB

robots

/// In The Name Of God
 
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
 
#include <bits/stdc++.h>
 
#define f first
#define s second
 
#define pb emplace_back
#define pp pop_back
#define mp make_pair
 
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
 
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
 
#define nl '\n'
#define ioi exit(0);
 
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
 
const int N = (int)500 + 1;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
 
const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
 
using namespace std;
 
int n, m, h;
char a[N][N];
 
int dp[55][N][N];
int id[10][10];
 
pair <int, int> res[N][N][4];
bool add[N][N][4];
bool was[N][N][4];
 

vector < pair <int, int> > q[N * N];
 
inline bool check(int x, int y) {
	return 0 <= x && x < n && 0 <= y && y < m && a[x][y] != 'x';
}
inline pair <int, int> go(int x, int y, int t) {
	if (a[x][y] == 'C') t = (t + 1) % 4;
	else if (a[x][y] == 'A') t = (t + 3) % 4;
	if (was[x][y][t]) return res[x][y][t];
	was[x][y][t] = 1;
	if (check(x + dx[t], y + dy[t])) return res[x][y][t] = go(x + dx[t], y + dy[t], t);
	return res[x][y][t] = {x, y};
}
 
int tin[N][N];
int main() {
	#ifdef IOI2018
		freopen ("in.txt", "r", stdin);
	#endif
	scanf ("%d%d%d", &h, &m, &n);
 
	int tmr = 0;
	for (int i = 0; i <= h; ++i) {
		for (int j = i; j <= h; ++j) {
			id[i][j] = tmr++;
		}
	}
	memset(dp, 0x3f, sizeof(dp));
	memset(res, -1, sizeof(res));

	for (int i = 0; i < n; ++i) {
		scanf ("%s", a[i]);
		for (int j = 0; j < m; ++j) {
			if (isdigit(a[i][j])) {
				int d = a[i][j] - '1';
				dp[id[d][d]][i][j] = 0;
			}
		}
	}	
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < m; ++j) {
			if (check(i, j)) {
				for (int t = 0; t < 4; t++) {
					go(i, j, t);
				}
			}
		}
	}

	tmr = 0;
	for (int len = 0; len < h; len++) {
		for (int l = 0; l + len < h; l++) {
			int r = l + len;
			for (int i = 0; i < n; i++) {
				for (int j = 0; j < m; j++) {
					for (int mid = l; mid < r; mid++) {
						dp[id[l][r]][i][j] = min(dp[id[l][r]][i][j], dp[id[l][mid]][i][j] + dp[id[mid + 1][r]][i][j]);
					}
				}
			}

			for (int i = 0; i < n; i++) {
				for (int j = 0; j < m; j++) {
					if (dp[id[l][r]][i][j] < inf) q[dp[id[l][r]][i][j]].pb(mp(i, j));
				}
			}

			++tmr;
			for (int cost = 0, up = n * m; cost <= up; cost++) {
				while (sz(q[cost])) {
					pair <int, int> v = q[cost].back();
					q[cost].pp();
					tin[v.f][v.s] = tmr;
					for (int i = 0; i < 4; i++) {
						pair <int, int> to = go(v.f, v.s, i);
						if (tin[to.f][to.s] != tmr && dp[id[l][r]][to.f][to.s] > dp[id[l][r]][v.f][v.s] + 1) {
							dp[id[l][r]][to.f][to.s] = dp[id[l][r]][v.f][v.s] + 1;
							q[dp[id[l][r]][to.f][to.s]].pb(to);
						}
					}
				}
				//q[cost].shrink_to_fit();
			}

		}
	}	
	int ans = inf;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			ans = min(ans, dp[id[0][h - 1]][i][j]);
		}
	}
	if (ans >= inf) ans = -1;
	cout << ans;
	ioi
}

Compilation message (stderr)

robots.cpp: In function 'int main()':
robots.cpp:68:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d%d%d", &h, &m, &n);
  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~
robots.cpp:80:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%s", a[i]);
   ~~~~~~^~~~~~~~~~~~
robots.cpp:105:91: warning: array subscript is above array bounds [-Warray-bounds]
       dp[id[l][r]][i][j] = min(dp[id[l][r]][i][j], dp[id[l][mid]][i][j] + dp[id[mid + 1][r]][i][j]);
                                                                              ~~~~~~~~~~~~~^
robots.cpp:105:88: warning: array subscript is above array bounds [-Warray-bounds]
       dp[id[l][r]][i][j] = min(dp[id[l][r]][i][j], dp[id[l][mid]][i][j] + dp[id[mid + 1][r]][i][j]);
                                                                              ~~~~~~~~~~^

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40