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36 lines
855 B
C++
36 lines
855 B
C++
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#include <bits/stdc++.h>
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using namespace std;
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int n, m;
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long long w[1005][1005], f[1005][1005][2];
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long long dfs(int x, int y, int from) {
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if (x < 1 || x > n || y < 1 || y > m) {
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return -0x3f3f3f3f;
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}
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if (f[x][y][from] != -0x3f3f3f3f) {
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return f[x][y][from];
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}
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if (from == 0) {
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f[x][y][from] = max({dfs(x + 1, y, 0), dfs(x, y - 1, 0), dfs(x, y - 1, 1)}) + w[x][y];
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}
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else {
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f[x][y][from] = max({dfs(x - 1, y, 1), dfs(x, y - 1, 0), dfs(x, y - 1, 1)}) + w[x][y];
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}
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return f[x][y][from];
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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 >> w[i][j];
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f[i][j][0] = f[i][j][1] = -0x3f3f3f3f;
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}
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}
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f[1][1][0] = f[1][1][1] = w[1][1];
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cout << dfs(n, m, 1) << endl;
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return 0;
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}
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