51 lines
1.1 KiB
C++
51 lines
1.1 KiB
C++
#include <bits/stdc++.h>
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using namespace std;
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typedef long long LL;
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const int N = 22;
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int n, m, mx, my;
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LL f[N][N]; //一定要开long long ，不然3 4 测试点过不了
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//增量数组，delta
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int d[8][2] = {
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{1, 2},
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{1, -2},
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{-1, 2},
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{-1, -2},
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{2, 1},
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{2, -1},
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{-2, 1},
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{-2, -1}};
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int ctrl[N][N];
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//搜索
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LL dfs(int x, int y) {
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//计算过，直接返回
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if (dp[x][y]) return dp[x][y];
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//走不了
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if (ctrl[x][y] || x > n || y > m) return dp[x][y] = 0;
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//如果是终点
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if (x == n && y == m) return dp[x][y] = 1;
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//如果都不是，那么需要依赖于右和下的和
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return dp[x][y] = dfs(x, y + 1) + dfs(x + 1, y);
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}
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int main() {
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cin >> n >> m >> mx >> my;
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//马的实际控制范围
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for (int i = 0; i < 8; i++) {
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int tx = mx + d[i][0], ty = my + d[i][1];
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if (tx >= 0 && tx <= n && ty >= 0 && ty <= m) ctrl[tx][ty] = 1;
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}
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//马所在的位置你也不能走，也踢你~
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ctrl[mx][my] = 1;
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//开始深搜
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cout << dfs(0, 0);
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return 0;
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}
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