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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define int              long long int
  4. #define double           long double
  5. #define print(a)         for(auto x : a) cout << x << " "; cout << endl
  6.  
  7.  
  8. const int M = 1000000007;
  9. const int N = 3e5+9;
  10. const int INF = 2e9+1;
  11. const int LINF = 2000000000000000001;
  12.  
  13. inline int power(int a, int b, int mod=M) {
  14.     int x = 1;
  15.     a %= mod;
  16.     while (b) {
  17.         if (b & 1) x = (x * a) % mod; 
  18.         a = (a * a) % mod;
  19.         b >>= 1;
  20.     }
  21.     return x;
  22. }
  23.  
  24.  
  25. //_ ***************************** START Below *******************************
  26.  
  27.  
  28.  
  29.  
  30. vector<int> a;
  31.  
  32. vector<pair<int,int>> consistency(int n){
  33.  
  34.     unordered_map<int,int> mp;
  35.     int k = 0;
  36.  
  37.     vector<pair<int,int>> ans;
  38.  
  39.     for(int i=0; i<n; i++){
  40.         if(mp.count(a[i])){
  41.             int j = mp[a[i]];
  42.             if(j>=k){
  43.                 mp.erase(a[i]);
  44.                 ans.push_back({k+1, i+1});
  45.                 k = i+1;
  46.             }
  47.         }
  48.         mp[a[i]] = i;
  49.     }
  50.  
  51.     int m = ans.size();
  52.     if(m>0) ans[m-1] = {ans[m-1].first, n};
  53.  
  54.     return ans;
  55.  
  56. }
  57.  
  58.  
  59.  
  60.  
  61.  
  62.  
  63.  
  64.  
  65.  
  66.  
  67.  
  68.  
  69.  
  70.  
  71.  
  72. vector<pair<int,int>> practice(int n){
  73.  
  74.  
  75. }
  76.  
  77.  
  78.  
  79.  
  80.  
  81. void solve() {
  82.  
  83.     int n;
  84.     cin>> n;
  85.  
  86.     a.resize(n);
  87.     for(int i=0; i<n; i++) cin >> a[i];
  88.  
  89.     auto ans = consistency(n);
  90.     if(ans.size() == 0){
  91.         cout << -1 << endl;
  92.         return;
  93.     }
  94.     cout << ans.size() << endl;
  95.     for(auto& t : ans) cout << t.first << " " << t.second << endl;
  96.  
  97.  
  98. }
  99.  
  100.  
  101.  
  102.  
  103.  
  104. int32_t main() {
  105.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  106.  
  107.     int t = 1;
  108.     // cin >> t;
  109.     while (t--) {
  110.         solve();
  111.     }
  112.  
  113.     return 0;
  114. }
Success #stdin #stdout 0.01s 5312KB
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https://ideone.com/Vo0mIz
language:
C++14 (gcc 8.3)
created:
1 day ago
visibility:
public

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