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47 lines
1013 B
47 lines
1013 B
#include <bits/stdc++.h>
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using namespace std;
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#define x first
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#define y second
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typedef pair<int, int> PII;
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const int N = 110;
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int n, m;
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int g[N][N];
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int d[N][N];
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int dx[] = {-1, 0, 1, 0};
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int dy[] = {0, 1, 0, -1};
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queue<PII> q;
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int bfs() {
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q.push({1, 1});
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memset(d, -1, sizeof d);
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d[1][1] = 0;
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while (q.size()) {
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if (~d[n][m]) break; // 不等于-1,表示已找到小哈,剪枝
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auto u = q.front();
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q.pop();
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for (int i = 0; i < 4; i++) {
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int tx = u.x + dx[i], ty = u.y + dy[i];
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if (tx == 0 || tx > n || ty == 0 || ty > m) continue;
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if (g[tx][ty] == 0 && d[tx][ty] == -1) {
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d[tx][ty] = d[u.x][u.y] + 1;
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q.push({tx, ty});
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}
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}
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}
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return d[n][m];
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}
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int main() {
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cin >> n >> m;
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for (int i = 1; i <= n; i++)
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for (int j = 1; j <= m; j++)
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cin >> g[i][j];
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cout << bfs() << endl;
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return 0;
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} |