Submission #53497

#	Time	Username	Problem	Language	Result	Execution time	Memory
53497		baactree	Match (CEOI16_match)	C++17	10 / 100	3 ms	624 KiB

match

#include <bits/stdc++.h>
using namespace std;
int n;
char str[100005];
int sum[100005];
bool possi[100005];
bool solve(int le, int ri) {
	if (le > ri)return true;
	stack<int> st;
	for (int i = le; i <= ri; i++) {
		if (!st.empty() && st.top() == str[i])st.pop();
		else st.push(str[i]);
		possi[i] = st.empty();
	}
	for (int i = ri; i > le; i--) {
		if (str[i] == str[le] && possi[ri]) {
			str[le] = '(';
			str[i] = ')';
			return solve(le + 1, i - 1) && solve(i + 1, ri);
		}
	}
	return false;
}
int main() {
	scanf("%s", str + 1);
	n = strlen(str + 1);
	for (int i = 1; i <= n; i++)
		sum[i] = sum[i - 1] ^ (1 << (str[i] - 'a'));
	if(solve(1, n))	printf("%s\n", str + 1);
	else printf("-1\n");
	return 0;
}

Compilation message (stderr)

match.cpp: In function 'int main()':
match.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", str + 1);
  ~~~~~^~~~~~~~~~~~~~~

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