Codeforces 585B Phillip and Trains（dp）

代码

#include <cstdio>
#include <cstring>
#include <queue>
#include <vector>
#include <algorithm>

using namespace std;
const int maxn = 105;
const int dir[3] = {-1, 0, 1};
typedef pair<int,int> pii;

int N, K, vis[maxn][3];
char G[3][maxn];

bool judge () {
queue<pii> que;
memset(vis, 0, sizeof(vis));

for (int i = 0; i < 3; i++) if (G[i][0] == 's') {
que.push(make_pair(0, i));
vis[0][i] = 1;
}

while (!que.empty()) {
pii cur = que.front();
que.pop();
int u = cur.first * 3;
int h = cur.second;
//printf("%d %d\n", u, h);

if (u + 1 >= N) return true;
if (G[h][u+1] != '.') continue;

for (int i = 0; i < 3; i++) {
int vh = h + dir[i], vv = u+1;

if (vh < 0 || vh >= 3) continue;

bool flag = true;
for (int j = 0; j <= 2 && flag; j++) {
if (vv + j >= N) return true;
if (G[vh][vv+j] != '.') flag = false;
}

if (flag) {
int t = (vv + 2) / 3;
if (!vis[t][vh]) {
que.push(make_pair(t, vh));
vis[t][vh] = 1;
}
}
}
}
return false;
}

int main () {
int cas;
scanf("%d", &cas);
while (cas--) {
scanf("%d%d", &N, &K);
for (int i = 0; i < 3; i++)
scanf("%s", G[i]);
printf("%s\n", judge() ? "YES" : "NO");
}
return 0;
}