File size: 3,183 Bytes
ff444f7 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 |
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
using int64 = long long;
int N, M;
vector<vector<int>> A;
vector<vector<int64>> dpl, dpr;
vector<vector<vector<int64>>> dp;
int64 rec(int dir, int x, int y) {
if (dp[dir][x][y] != -1LL) {
return dp[dir][x][y];
}
int64 res = dpr[0][0];
if (dir) {
int64 extra_exit = (y + 2 < M) ? dpr[x][y + 2] : 0;
int64 max_cost = extra_exit;
for (int ty = y; ty >= 0; --ty) {
int64 best_entrance = 0LL;
if (x) {
best_entrance = max(best_entrance, dpl[x - 1][ty]);
if (ty != y) {
best_entrance = max(best_entrance, dpl[x - 1][ty + 1]);
}
}
int64 best_exit = extra_exit;
if (x + 1 != N && ty + 1 != M) {
best_exit = max(best_exit, dpr[x + 1][ty + 1]);
}
max_cost = max(max_cost, best_entrance + best_exit);
if (ty) {
best_entrance = max(best_entrance, dpl[x][ty - 1]);
}
int64 local_max_cost = max(max_cost, best_entrance + best_exit);
if (x + 1 != N || !ty) {
int64 cur = (x + 1 == N) ? 0LL : rec(dir ^ 1, x + 1, ty);
cur = max(cur, local_max_cost);
res = min(res, cur);
}
}
} else {
int64 extra_entrance = (x - 2 >= 0) ? dpl[x - 2][y] : 0;
int64 max_cost = extra_entrance;
for (int tx = x; tx < N; ++tx) {
int64 best_exit = 0LL;
if (y + 1 != M) {
best_exit = max(best_exit, dpr[tx][y + 1]);
if (tx != x) {
best_exit = max(best_exit, dpr[tx - 1][y + 1]);
}
}
int64 best_entrance = extra_entrance;
if (y && tx) {
best_entrance = max(best_entrance, dpl[tx - 1][y - 1]);
}
max_cost = max(max_cost, best_entrance + best_exit);
if (tx + 1 != N) {
best_exit = max(best_exit, dpr[tx + 1][y]);
}
int64 local_max_cost = max(max_cost, best_entrance + best_exit);
if (y || tx + 1 == N) {
int64 cur = y ? rec(dir ^ 1, tx, y - 1) : 0LL;
cur = max(cur, local_max_cost);
res = min(res, cur);
}
}
}
return dp[dir][x][y] = res;
}
int64 solve() {
cin >> N >> M;
A.assign(N, vector<int>(M));
for (int i = 0; i < N; i++) {
for (int j = 0; j < M; j++) {
cin >> A[i][j];
}
}
dpl.assign(N, vector<int64>(M));
dpr.assign(N, vector<int64>(M));
for (int i = 0; i < N; i++) {
for (int j = 0; j < M; j++) {
dpl[i][j] = A[i][j];
if (i) {
dpl[i][j] = max(dpl[i][j], A[i][j] + dpl[i - 1][j]);
}
if (j) {
dpl[i][j] = max(dpl[i][j], A[i][j] + dpl[i][j - 1]);
}
}
}
for (int i = N - 1; i >= 0; i--) {
for (int j = M - 1; j >= 0; j--) {
dpr[i][j] = A[i][j];
if (i + 1 != N) {
dpr[i][j] = max(dpr[i][j], A[i][j] + dpr[i + 1][j]);
}
if (j + 1 != M) {
dpr[i][j] = max(dpr[i][j], A[i][j] + dpr[i][j + 1]);
}
}
}
dp.assign(2, vector<vector<int64>>(N, vector<int64>(M, -1LL)));
return min(rec(0, 0, M - 1), rec(1, 0, M - 1));
}
int main() {
int T;
cin >> T;
for (int t = 1; t <= T; t++) {
cout << "Case #" << t << ": " << solve() << endl;
}
return 0;
}
|