Submission #48087

#	Time	Username	Problem	Language	Result	Execution time	Memory
48087		Extazy	Match (CEOI16_match)	C++17	37 / 100	2021 ms	24792 KiB

match

#include <bits/stdc++.h>
#define endl '\n'

using namespace std;

const int N = 100007;

int n;
char a[N],ans[N];

bool can(int l, int r) {
  stack < char > s;
  int i;

  for(i=l;i<=r;i++) {
    if(!s.empty() && s.top()==a[i]) s.pop();
    else s.push(a[i]);
  }

  return s.empty();
}

void solve(int l, int r) {
  if(l>r) return;
  if(a[l]==a[r]) {
    ans[l]='(';
    ans[r]=')';
    solve(l+1,r-1);
    return;
  }

  int i,mid=(l+r)/2;
  stack < int > s;

  for(i=r;i>=l;i--) {
    if(!s.empty() && s.top()==a[i]) s.pop();
    else s.push(a[i]);

    if(s.empty() && a[i-1]==a[l]) {
      ans[l]='(';
      ans[i-1]=')';
      solve(l+1,i-2);
      solve(i,r);
      return;
    }
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int i;

  scanf("%s", a+1);
  n=strlen(a+1);

  if(!can(1,n)) {
    printf("-1\n");
    return 0;
  }
    
  solve(1,n);
  for(i=1;i<=n;i++) {
    printf("%c", ans[i]);
  }
  printf("\n");

  return 0;
}

Compilation message (stderr)

match.cpp: In function 'void solve(int, int)':
match.cpp:32:9: warning: unused variable 'mid' [-Wunused-variable]
   int i,mid=(l+r)/2;
         ^~~
match.cpp: In function 'int main()':
match.cpp:54:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s", a+1);
   ~~~~~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 27 / 27
• Subtask 3: 0 / 63