Submission #124401

#	Time	Username	Problem	Language	Result	Execution time	Memory
124401		eriksuenderhauf	Match (CEOI16_match)	C++11	37 / 100	2017 ms	18020 KiB

match

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
#define mem(a,v) memset((a), (v), sizeof (a))
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%I64d", &(n))
#define nai(a, n) for (int i = 0; i < (n); i++) ni(a[i])
#define nal(a, n) for (int i = 0; i < (n); i++) nl(a[i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%I64d\n", (n))
#define pii pair<int, int>
#define pil pair<int, long long>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vil vector<pil>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int MOD = 1e9 + 7;
const int INF = 1e9 + 7;
const int MAXN = 1e6 + 5;
const double eps = 1e-9;
char str[MAXN];
int a[MAXN];

void solve(int l, int r) {
	if (l > r) return;
	if (str[l] == str[r]) {
		a[r] = 1;
		solve(l+1, r-1);
		return;
	}
	stack<int> st;
	st.push(l);
	int mx = l;
	for (int i = l+1; i <= r; i++) {
		if (!st.empty() && str[i] == str[st.top()])
			st.pop();
		else
			st.push(i);
		if (st.empty() && str[i] == str[l])
			mx = i;
	}
	assert(st.empty());
	a[mx] = 1;
	solve(l+1,mx-1);
	solve(mx+1,r);
}

int main() {
	scanf("%s", str);
	int n = strlen(str);
	if (n & 1) return !printf("-1\n");
	stack<int> st;
	st.push(0);
	for (int i = 1; i < n; i++) {
		if (!st.empty() && str[i] == str[st.top()])
			st.pop();
		else
			st.push(i);
	}
	if (!st.empty())
		return !printf("-1\n");
	solve(0, n-1);
	for (int i = 0; i < n; i++)
		if (a[i])
			printf(")");
		else
			printf("(");
    return 0;
}

Compilation message (stderr)

match.cpp: In function 'int main()':
match.cpp:65:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", str);
  ~~~~~^~~~~~~~~~~

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