题目意思
存在格子规定方向,存在格子随意走动,不存在不能走的格子,只需要输出可以到达终点的某一条路径即可。
解题思路
BFS,直接对地图剖解,把方向字母用数字代替)其实也可以不换后面明显一点就是了,后面通过BFS记录当前走的方向,走到终点。
再一次方向走图,记录每个点是如何过来的。
再输出答案就行了!
#pragma GCC target("avx,sse2,sse3,sse4,popcnt") #pragma GCC optimize("O2,O3,Ofast,inline,unroll-all-loops,-ffast-math") #include <bits/stdc++.h> using namespace std; #define js ios::sync_with_stdio(false);cin.tie(0); cout.tie(0) #define all(vv) (vv).begin(), (vv).end() #define endl "\n" #define pai pair<int, int> #define fi first #define se second typedef long long ll; typedef unsigned long long ull; typedef long double ld; const ll MOD = 1e9 + 7; inline ll read() { ll s = 0, w = 1; char ch = getchar(); for (; !isdigit(ch); ch = getchar()) if (ch == '-') w = -1; for (; isdigit(ch); ch = getchar()) s = (s << 1) + (s << 3) + (ch ^ 48); return s * w; } inline void write(ll x) { if (!x) { putchar('0'); return; } char F[40]; ll tmp = x > 0 ? x : -x; if (x < 0)putchar('-'); int cnt = 0; while (tmp > 0) { F[cnt++] = tmp % 10 + '0'; tmp /= 10; } while (cnt > 0)putchar(F[--cnt]); } inline ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; } ll qpow(ll a, ll b) { ll ans = 1; while (b) { if (b & 1) ans *= a; b >>= 1; a *= a; } return ans; } ll qpow(ll a, ll b, ll mod) { ll ans = 1; while (b) { if (b & 1)(ans *= a) %= mod; b >>= 1; (a *= a) %= mod; }return ans % mod; } inline int lowbit(int x) { return x & (-x); } const int N = 1000 + 7; int mp[N][N]; int vis[N][N]; int p[N][N]; int n, m, sx, sy, tx, ty; int dx[] = { 0,-1,1,0,0 }; int dy[] = { 0,0,0,-1,1 }; int main() { js; cin >> n >> m >> sx >> sy >> tx >> ty; for (int i = 1; i <= n; ++i) for (int j = 1; j <= m; ++j) { char ch; cin >> ch; if (ch == '.') mp[i][j] == 0; else if (ch == 'w') mp[i][j] = 1; else if (ch == 's') mp[i][j] = 2; else if (ch == 'a') mp[i][j] = 3; else if (ch == 'd') mp[i][j] = 4; } queue<pai> q; q.push({ sx,sy }); vis[sx][sy] = 1; while (q.size()) { pai now = q.front(); q.pop(); int x = now.first, y = now.second; if (x == tx and y == ty) break; if (mp[x][y]) { int xx = x + dx[mp[x][y]], yy = y + dy[mp[x][y]]; if (xx >= 1 and xx <= n and yy >= 1 and yy <= m and !vis[xx][yy]) q.push({ xx,yy }), vis[xx][yy] = 1, p[xx][yy] = mp[x][y]; } else { for (int i = 1; i <= 4; ++i) { int xx = x + dx[i], yy = y + dy[i]; if (xx >= 1 and xx <= n and yy >= 1 and yy <= m and !vis[xx][yy]) q.push({ xx,yy }), vis[xx][yy] = 1, p[xx][yy] = i; } } } int x = tx, y = ty; while (x != sx or y != sy) { //反向走回起点并记录路程 int xx = x - dx[p[x][y]], yy = y - dy[p[x][y]]; mp[xx][yy] = p[x][y]; x = xx, y = yy; } cout << n << ' ' << m << ' ' << sx << ' ' << sy << ' ' << tx << ' ' << ty << endl; for (int i = 1; i <= n; ++i) { for (int j = 1; j <= m; ++j) if (!mp[i][j] or mp[i][j] == 1) cout << 'w'; //终点没走过,随便输出一个 else if (mp[i][j] == 2) cout << 's'; else if (mp[i][j] == 3) cout << 'a'; else if (mp[i][j] == 4) cout << 'd'; cout << endl; } return 0; }