Submission #483451

# Submission time Handle Problem Language Result Execution time Memory
483451 2021-10-29T15:05:12 Z XII Round words (IZhO13_rowords) C++17
100 / 100
176 ms 63044 KB
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define fi first
#define se second
#define mp make_pair
#define eb emplace_back
#define ALL(x) (x).begin(), (x).end()

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define FORU(i, a, b) for(int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)

#define IOS cin.tie(0)->sync_with_stdio(false);
#define PROB "rowords"
void Fi(){
    if(fopen(PROB".in", "r")){
        freopen(PROB".in", "r", stdin);
        freopen(PROB".out", "w", stdout);
    }
}

const int N = 2e3 + 1;
int dp[N * 2][N], t[N * 2][N];
int n, m, ans;
string s, p;

const int dx[] = {0, -1, -1};
const int dy[] = {-1, -1, 0};

void calc(){
    memset(dp, 0, sizeof(dp));
    memset(t, -1, sizeof(t));
    FORU(i, 1, n * 2) t[i][0] = 2;
    FORU(j, 1, m) t[0][j] = 0;
    FORU(i, 1, n * 2) FORU(j, 1, m){
        auto selection = {
            dp[i][j - 1],
            dp[i - 1][j - 1] + (s[i] == p[j]),
            dp[i - 1][j]
        };
        dp[i][j] = *max_element(ALL(selection));
        t[i][j] = max_element(ALL(selection)) - selection.begin();
    }
    ans = max(ans, dp[n][m]);
    FORU(row, 1, n){
        {
            int i = row, j;
            for(j = 1; j <= m && t[i][j] != 1; ++j);
            if(j <= m){
                t[i][j] = 0;
                while(i < n * 2 && j <= m){
                    if(t[i + 1][j] == 2) t[++i][j] = 0;
                    else if(j == m) break;
                    else if(t[i + 1][j + 1] == 1) t[++i][++j] = 0;
                    else ++j;
                }
            }
        }
        {
            int tmp = 0;
            for(int i = n + row, j = m; i > row && j > 0;){
                int d = t[i][j];
                if(d == 1) ++tmp;
                i += dx[d], j += dy[d];
            }
            ans = max(ans, tmp);
        }
    }
}

int main(){
    IOS;
    Fi();
    cin >> s >> p;
    n = s.size(), m = p.size();
    s = " " + s + s;
    p = " " + p;
    calc();
    reverse(p.begin() + 1, p.begin() + m + 1);
    calc();
    cout << ans;
    return 0;
}

Compilation message

rowords.cpp: In function 'void Fi()':
rowords.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen(PROB".in", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
rowords.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen(PROB".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 33 ms 62924 KB Output is correct
2 Correct 33 ms 63008 KB Output is correct
3 Correct 33 ms 63012 KB Output is correct
4 Correct 34 ms 62912 KB Output is correct
5 Correct 33 ms 63044 KB Output is correct
6 Correct 45 ms 63000 KB Output is correct
7 Correct 60 ms 62924 KB Output is correct
8 Correct 98 ms 62956 KB Output is correct
9 Correct 126 ms 62988 KB Output is correct
10 Correct 99 ms 62924 KB Output is correct
11 Correct 105 ms 62920 KB Output is correct
12 Correct 84 ms 63004 KB Output is correct
13 Correct 142 ms 62924 KB Output is correct
14 Correct 125 ms 62996 KB Output is correct
15 Correct 130 ms 62924 KB Output is correct
16 Correct 116 ms 63000 KB Output is correct
17 Correct 118 ms 62972 KB Output is correct
18 Correct 154 ms 63012 KB Output is correct
19 Correct 94 ms 62924 KB Output is correct
20 Correct 162 ms 62992 KB Output is correct
21 Correct 105 ms 62924 KB Output is correct
22 Correct 129 ms 62924 KB Output is correct
23 Correct 146 ms 62992 KB Output is correct
24 Correct 153 ms 62940 KB Output is correct
25 Correct 176 ms 62924 KB Output is correct