Submission #362092

# Submission time Handle Problem Language Result Execution time Memory
362092 2021-02-01T17:34:53 Z Sparky_09 Round words (IZhO13_rowords) C++17
100 / 100
408 ms 66540 KB
#include "bits/stdc++.h"
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define trav(a, x) for(auto& a : x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vpi;
 
void usaco(string s){
  freopen((s+".in").c_str(), "r", stdin);
  freopen((s+".out").c_str(), "w", stdout);
}
 
int n, m, start=0, ans = 0;
string s, t;
int dp[4100][2100];
pii before[4100][2100];
 
 
int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);
#ifdef LOCAL_DEFINE
	freopen("input.txt", "r", stdin);
#endif
  cin >> s >> t;
  //cerr << s << ' ' << t << '\n';
  n = s.size(); m = t.size();
  for(int i = 0; i < 4100; i++) for(int j = 0; j < 2100; j++) dp[i][j] = (int)1e9;
  dp[0][0] = 0;
  for(int i = 0; i <= 2*n; i++){
    for(int j = 0; j <= m; j++){
      if(i==0 and j==0) continue;
      //dp[i][j] = 1e9;
      
      if(j > 0 and dp[i][j] > dp[i][j-1] + 1){
        dp[i][j] = dp[i][j-1] + 1;
        before[i][j] = make_pair(i, j-1);
      }
      if(i > 0 and j > 0 and s[(i - 1)%n] ==  t[j-1] and dp[i][j] > dp[i-1][j-1] + 1){
        dp[i][j] = dp[i-1][j-1] + 1;
        before[i][j] = make_pair(i-1, j-1);
      }
      if(i > 0 and dp[i][j] > dp[i-1][j] + 1){
        dp[i][j] = dp[i-1][j] + 1;
        before[i][j] = make_pair(i-1, j);
      }
      //cerr << before[i][j].first << ' ' << before[i][j].second << ' ' << i << ' ' << j << '\n';
    }
  }
  
  auto back = [&](int n1, int m1){
  	int sub = 0;
  	int temp = 0;
  	//cerr << n1 << ' ' << m1 << '\n';
    while(n1 != start or m1){
      n1 = before[n1][m1].first; m1 = before[n1][m1].second;
      sub++;
      //if(temp<10)
      	//cerr << "here" << ' ' << n1 << ' ' << m1 << '\n'; //here is the error
      //temp++;
    }
    //cerr<<"done";
    return sub;
  };
 
  auto newstart = [&](){
    int i = start, j = 1;
    while(j <= m and (before[i][j] != make_pair(i - 1, j - 1))){
      j++;
    }
    if(j > m){
      return;
    }
    before[i][j] = make_pair(i, j - 1);
    //move one forward start is ahead now, we process next set
    while(i < 2*n and j < m){
      if(before[i+1][j] == make_pair(i, j)){
        i++;
        before[i][j] = make_pair(i, j-1);
      }
      else if(before[i+1][j+1] == make_pair(i, j)){
        i++; j++;
        before[i][j] = make_pair(i, j-1);
      }
      else{
        j++;
      }
    }
    while(i < 2*n and before[i+1][j] == make_pair(i, j)){
      i++; before[i][j] = make_pair(i, j-1);
    }
  };
  start = 0;
  ans = max(ans, n + m - back(n, m));
  for(int i = 1; i < n; i++){
    start++; newstart();
    ans = max(ans, n+m-back(n+i,m));
  }
  reverse(t.begin(), t.end());
  //memset(dp, 0x3f, sizeof dp);
  for(int i = 0; i <= 2*n; i++){
    for(int j = 0; j <= m; j++){
      if(i==0 and j==0) continue;
      dp[i][j]=1e9;
      if(j > 0 and dp[i][j] > dp[i][j-1] + 1){
        dp[i][j] = dp[i][j-1] + 1;
        before[i][j] = {i, j-1};
      }
      if(i > 0 and j > 0 and s[(i - 1)%n] ==  t[j-1] and dp[i][j] > dp[i-1][j-1] + 1){
        dp[i][j] = dp[i-1][j-1] + 1;
        before[i][j] = {i-1, j-1};
      }
      if(i > 0 and dp[i][j] > dp[i-1][j] + 1){
        dp[i][j] = dp[i-1][j] + 1;
        before[i][j] = {i-1, j};
      }
 
    }
  }
  start = 0;
  ans = max(ans, n + m - back(n, m));
  for(int i = 1; i < n; i++){
    start++; newstart();
    ans = max(ans, n+m-back(n+i,m));
  }
  cout << ans << '\n';
}

Compilation message

rowords.cpp: In lambda function:
rowords.cpp:57:8: warning: unused variable 'temp' [-Wunused-variable]
   57 |    int temp = 0;
      |        ^~~~
rowords.cpp: In function 'void usaco(std::string)':
rowords.cpp:13:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   13 |   freopen((s+".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
rowords.cpp:14:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   14 |   freopen((s+".out").c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 23 ms 34156 KB Output is correct
2 Correct 22 ms 34156 KB Output is correct
3 Correct 22 ms 34156 KB Output is correct
4 Correct 22 ms 34412 KB Output is correct
5 Correct 22 ms 34412 KB Output is correct
6 Correct 62 ms 43628 KB Output is correct
7 Correct 100 ms 57720 KB Output is correct
8 Correct 186 ms 57836 KB Output is correct
9 Correct 182 ms 57708 KB Output is correct
10 Correct 159 ms 57708 KB Output is correct
11 Correct 175 ms 60140 KB Output is correct
12 Correct 205 ms 63852 KB Output is correct
13 Correct 251 ms 63724 KB Output is correct
14 Correct 200 ms 61164 KB Output is correct
15 Correct 234 ms 65516 KB Output is correct
16 Correct 210 ms 59884 KB Output is correct
17 Correct 233 ms 58672 KB Output is correct
18 Correct 289 ms 66540 KB Output is correct
19 Correct 153 ms 57708 KB Output is correct
20 Correct 270 ms 62956 KB Output is correct
21 Correct 252 ms 51692 KB Output is correct
22 Correct 294 ms 55532 KB Output is correct
23 Correct 325 ms 58416 KB Output is correct
24 Correct 357 ms 59884 KB Output is correct
25 Correct 408 ms 64364 KB Output is correct