mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
83 lines
2.0 KiB
C++
83 lines
2.0 KiB
C++
#include<cstdio>
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#include<algorithm>
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#include<cstring>
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#include<vector>
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#define MAXN 2010
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using namespace std;
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int arr[MAXN];
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char str[MAXN];
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bool flag;
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int idx[MAXN];
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int cnt[MAXN];
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int st[2][MAXN];
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int belong[MAXN];
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int n;
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vector<int> pos[MAXN];
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void dfs(int x, int p1, int p2) {
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if (x > n) {
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flag = true;
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}
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if (flag) {
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return;
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}
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if (p1 > 0 && p2 > 0
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&& arr[st[0][min(p1, p2)]] != arr[st[1][min(p1, p2)]]) {
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return;
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}
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if (belong[x] == 0) {
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st[0][p1 + 1] = x;
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dfs(x + 1, p1 + 1, p2);
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} else if (belong[x] == 1) {
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st[1][p2 + 1] = x;
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dfs(x + 1, p1, p2 + 1);
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} else {
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st[0][p1 + 1] = x;
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belong[pos[arr[x]][2]] = 1;
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dfs(x + 1, p1 + 1, p2);
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if (!flag) {
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st[1][p2 + 1] = x;
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belong[pos[arr[x]][2]] = 0;
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dfs(x + 1, p1, p2 + 1);
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belong[pos[arr[x]][2]] = -1;
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}
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}
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}
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int main() {
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int T;
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int i;
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scanf("%d", &T);
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while (T--) {
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scanf("%d", &n);
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memset(idx, 0, sizeof(idx));
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memset(cnt, 0, sizeof(cnt));
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for (i = 1; i <= n; i++) {
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scanf("%d", &arr[i]);
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cnt[arr[i]]++;
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idx[i] = cnt[arr[i]];
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pos[arr[i]].clear();
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}
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memset(belong, -1, sizeof(belong));
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for (i = 1; i <= n; i++) {
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if (idx[i] == 1) {
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belong[i] = 0;
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} else if (idx[i] == 2 && cnt[arr[i]] == 2) {
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belong[i] = 1;
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} else if (idx[i] == 4) {
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belong[i] = 1;
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}
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pos[arr[i]].push_back(i);
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}
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flag = false;
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dfs(1, 0, 0);
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for (i = 1; i <= (n >> 1); i++) {
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str[st[0][i]] = '0';
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str[st[1][i]] = '1';
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}
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for (i = 1; i <= n; i++) {
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putchar(str[i]);
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}
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putchar('\n');
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}
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return 0;
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}
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