답안 #945096

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
945096 2024-03-13T11:53:24 Z atom Bomb (IZhO17_bomb) C++17
98 / 100
1000 ms 131072 KB
    #include "bits/stdc++.h"
    // @JASPER'S BOILERPLATE
    using namespace std;
    using ll = long long;
     
    #ifdef JASPER
    #include "debug.h"
    #else
    #define debug(...) 166
    #endif
     
    signed main() {
        cin.tie(0) -> sync_with_stdio(0);
        #ifdef JASPER
            freopen("in1", "r", stdin);
        #endif
     
        int n, m;
        cin >> n >> m;
        vector <vector <int>> a(n + 5, vector <int> (m + 5, 0));
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= m; ++j) {
                char x; cin >> x;
                a[i][j] = x - '0';
            }
        }
     
        // for (int i = 1; i <= n; ++i) 
        //     for (int j = 1; j <= m; ++j)
        //         cout << a[i][j] << " \n"[j == m]; 
     
        //sub1: shortest consecutive 1ss
        if (n == 1 || m == 1) {
            if (n == 1) {
                int ans = 1e9;
                for (int i = 1; i <= m; ++i) {
                    if (a[1][i] == 0) continue;
                    int cur = 0;
                    while (i <= m && a[1][i]) { 
                        ++cur;
                        ++i;
                    }
                    ans = min(ans, cur);
                }
                cout << ans << "\n";
                return 0;
            }
            if (m == 1) {
                int ans = 1e9;
                for (int i = 1; i <= n; ++i) {
                    if (a[i][1] == 0) continue;
                    int cur = 0;
                    while (i <= n && a[i][1]) { 
                        ++cur;
                        ++i;
                    }
                    ans = min(ans, cur);
                }
                cout << ans << "\n";
                return 0;
            }
        }
     
        // sub3
        // if (n <= 450 && m <= 450) {
        //     vector <vector <int>> prf(n + 5, vector <int> (m + 5, 0));
        //     int earth = 0;
        //     for (int i = 1; i <= n; ++i) {
        //         for (int j = 1; j <= m; ++j) {
        //             earth += (a[i][j] == 0);
        //             prf[i][j] = prf[i][j - 1] + prf[i - 1][j] - prf[i - 1][j - 1] + a[i][j];
        //         }
        //     }
     
        //     int ans = 0;
        //     for (int x = 1; x <= n; ++x) {
        //         for (int y = 1; y <= m; ++y) {
        //             if (x * y <= ans) continue;
     
        //             // prf(l)++, prf(r + 1)--;
        //             vector <vector <int>> dmg(n + 2, vector <int> (m + 2, 0));
     
        //             for (int i = 1; i + x - 1 <= n; ++i) {
        //                 for (int j = 1; j + y - 1 <= m; ++j) {
        //                     int I = i + x - 1, J = j + y - 1;
        //                     if (prf[I][J] + prf[i - 1][j - 1] - prf[I][j - 1] - prf[i - 1][J] == x * y) {
        //                         dmg[i][j] += 1;
        //                         dmg[I + 1][j] -= 1;
        //                         dmg[i][J + 1] -= 1;
        //                         dmg[I + 1][J + 1] += 1;
        //                     }
        //                 }
        //             }
     
        //             for (int i = 1; i <= n; ++i)
        //                 for (int j = 1; j <= m; ++j)
        //                     dmg[i][j] += dmg[i - 1][j] + dmg[i][j - 1] - dmg[i - 1][j - 1];
     
        //             bool valid = 1;
        //             for (int i = 1; i <= n; ++i) {
        //                 for (int j = 1; j <= m; ++j) {
        //                     if (a[i][j] && !dmg[i][j])
        //                         valid = 0;
        //                 }
        //             }
        //             if (valid) ans = max(ans, x * y);
        //         }
        //     }
     
        //     cout << ans << "\n";
        //     return 0;
        // }
        
     
     
        // two pointer to optimize
        vector <vector <int>> lt(n + 5, vector <int> (m + 5, 0)), rt(n + 5, vector <int> (m + 5, 0));
        vector <int> w(n + 5, 1e9); // ans(i) : W when H = i
        int min_h = 1e9;// minimum vertical strip of 1s;
     
        for (int _i = 0; _i <= 1; _i++) {
            for (int i = 1; i <= n; ++i) {
                for (int j = 1; j <= m; ++j)
                    lt[i][j] = a[i][j]? (lt[i][j - 1] + 1) : 0;
     
                for (int j = m; j >= 1; --j)
                    rt[i][j] = a[i][j]? (rt[i][j + 1] + 1) : 0;
     
                for (int j = 1; j <= m; ++j)
                    if (a[i][j]) w[1] = min(w[1], rt[i][j] + lt[i][j] - 1);
            }
            // find feasible height
            for (int j = 1; j <= m; ++j) {
                int k = 0; // length of consecutive 1s of current column
                int l = 1e9, r = 1e9;
                for (int i = 1; i <= n; ++i) {
                    if (a[i][j]) {
                        ++k;
                        l = min(l, lt[i][j]);
                        r = min(r, rt[i][j]);
                        w[k] = min(w[k], r + l - 1);
                    }
                    else {
                        if (k) min_h = min(min_h, k);
                        l = r = 1e9;
                        k = 0;
                    }
                }
            }
     
            for (int i = 1; i <= n / 2; ++i) {
                for (int j = 1; j <= m; ++j)
                    swap(a[i][j], a[n - i + 1][j]);
            }
     
        }
     
        int ans = 0;
        for (int h = 1; h <= min_h; ++h) {
            w[h + 1] = min(w[h + 1], w[h]); // width is bounded by the minimum horizontal strip
            ans = max(ans, w[h] * h);
        }
     
        cout << ans << "\n";
    }
# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 344 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 1 ms 348 KB Output is correct
19 Correct 1 ms 348 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 0 ms 424 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 1 ms 348 KB Output is correct
25 Correct 1 ms 348 KB Output is correct
26 Correct 1 ms 348 KB Output is correct
27 Correct 3 ms 1372 KB Output is correct
28 Correct 3 ms 1628 KB Output is correct
29 Correct 4 ms 1884 KB Output is correct
30 Correct 5 ms 2652 KB Output is correct
31 Correct 4 ms 2140 KB Output is correct
32 Correct 4 ms 2140 KB Output is correct
33 Correct 6 ms 2908 KB Output is correct
34 Correct 2 ms 1372 KB Output is correct
35 Correct 5 ms 2908 KB Output is correct
36 Correct 8 ms 2904 KB Output is correct
37 Correct 1 ms 348 KB Output is correct
38 Execution timed out 2244 ms 131072 KB Time limit exceeded
39 Correct 0 ms 344 KB Output is correct
40 Correct 36 ms 9560 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 1 ms 348 KB Output is correct
43 Correct 407 ms 74384 KB Output is correct
44 Correct 7 ms 2904 KB Output is correct
45 Correct 388 ms 74580 KB Output is correct
46 Correct 360 ms 74256 KB Output is correct
47 Correct 397 ms 74240 KB Output is correct
48 Correct 400 ms 74240 KB Output is correct
49 Correct 484 ms 74388 KB Output is correct
50 Correct 371 ms 74384 KB Output is correct
51 Correct 367 ms 74256 KB Output is correct
52 Correct 371 ms 74384 KB Output is correct
53 Correct 368 ms 74244 KB Output is correct
54 Correct 292 ms 74320 KB Output is correct
55 Correct 281 ms 74256 KB Output is correct
56 Execution timed out 2683 ms 131072 KB Time limit exceeded
57 Correct 271 ms 74320 KB Output is correct
58 Correct 291 ms 74384 KB Output is correct
59 Correct 275 ms 74384 KB Output is correct
60 Correct 345 ms 74236 KB Output is correct
61 Correct 485 ms 74636 KB Output is correct
62 Correct 495 ms 74492 KB Output is correct
63 Correct 487 ms 74328 KB Output is correct
64 Correct 266 ms 74384 KB Output is correct
65 Correct 349 ms 74380 KB Output is correct
66 Correct 355 ms 74512 KB Output is correct
67 Correct 375 ms 74328 KB Output is correct
68 Correct 432 ms 74384 KB Output is correct
69 Correct 312 ms 74328 KB Output is correct
70 Correct 142 ms 47856 KB Output is correct
71 Correct 243 ms 74324 KB Output is correct
72 Correct 274 ms 74384 KB Output is correct
73 Correct 296 ms 74384 KB Output is correct
74 Correct 280 ms 74384 KB Output is correct
75 Correct 287 ms 74380 KB Output is correct
76 Correct 289 ms 74380 KB Output is correct
77 Correct 300 ms 74580 KB Output is correct
78 Correct 291 ms 74320 KB Output is correct
79 Correct 197 ms 74380 KB Output is correct
80 Correct 220 ms 74244 KB Output is correct
81 Correct 196 ms 74384 KB Output is correct
82 Correct 306 ms 74380 KB Output is correct
83 Correct 295 ms 74324 KB Output is correct
84 Correct 195 ms 74320 KB Output is correct
85 Correct 309 ms 74380 KB Output is correct
86 Correct 466 ms 74576 KB Output is correct
87 Correct 289 ms 74384 KB Output is correct
88 Correct 301 ms 74256 KB Output is correct
89 Correct 340 ms 74576 KB Output is correct
90 Correct 171 ms 47852 KB Output is correct
91 Correct 309 ms 74384 KB Output is correct
92 Correct 340 ms 74384 KB Output is correct
93 Correct 459 ms 74236 KB Output is correct
94 Correct 337 ms 74384 KB Output is correct
95 Correct 307 ms 74384 KB Output is correct
96 Correct 291 ms 74384 KB Output is correct
97 Correct 473 ms 74384 KB Output is correct
98 Correct 300 ms 74240 KB Output is correct
99 Correct 330 ms 74388 KB Output is correct
100 Correct 448 ms 74388 KB Output is correct