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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. int consistency1(int n){
  33.  
  34. 	int ans = 0;
  35.  
  36. 	for(int j=1; j<=n-2; j++){
  37.  
  38. 		int ct1 = 0;
  39. 		int i = j-1;
  40. 		while(i>=0){
  41. 			if(a[i] > a[j]) ct1++;
  42. 			i--;
  43. 		}
  44.  
  45. 		int ct2 = 0;
  46. 		int k = j+1;
  47. 		while(k<n){
  48. 			if(a[k] > a[j]) ct2++;
  49. 			k++;
  50. 		}
  51.  
  52. 		ans += (ct1 * ct2);
  53. 	}
  54.  
  55. 	return ans;
  56.  
  57. }
  58.  
  59.  
  60.  
  61.  
  62.  
  63.  
  64.  
  65.  
  66. int consistency2(int n){
  67.  
  68. 	vector<int> pGreaterThan(n);
  69.  
  70. 	for(int i=1; i<n; i++){
  71. 		int ct = 0;
  72. 		int j = i-1;
  73. 		while(j>=0){
  74. 			if(a[j] > a[i]) ct++;
  75. 			j--;
  76. 		}
  77. 		pGreaterThan[i] = ct;
  78. 	}
  79.  
  80. 	vector<int> sSmallerThan(n);
  81.  
  82. 	for(int i=n-2; i>=0; i--){
  83. 		int ct = 0;
  84. 		int j = i+1;
  85. 		while(j<n){
  86. 			if(a[j] < a[i]) ct++;
  87. 			j++;
  88. 		}
  89. 		sSmallerThan[i] = ct;
  90. 	}
  91.  
  92.  
  93. 	int ans = 0;
  94. 	for(int j=1; j<=n-3; j++){
  95. 		for(int k=j+1; k<=n-2; k++){
  96. 			int x = a[j];
  97. 			int y = a[k];
  98.  
  99. 			if(x>=y) continue;
  100.  
  101. 			int ct1 = pGreaterThan[j];
  102. 			int ct2 = sSmallerThan[k];
  103.  
  104. 			ans += (ct1 * ct2);
  105. 		}
  106. 	}
  107.  
  108. 	return ans;
  109.  
  110. }
  111.  
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  139.  
  140.  
  141.  
  142. int practice(int n){
  143.  
  144.  
  145.     return 0;
  146. }
  147.  
  148.  
  149.  
  150.  
  151.  
  152. void solve() {
  153.  
  154.     int n;
  155.     cin>> n;
  156.  
  157.     a.resize(n);
  158.     for(int i=0; i<n; i++) cin >> a[i];
  159.  
  160.     cout << consistency1(n) << " , Followup => " << consistency2(n) << endl;
  161.  
  162.  
  163. }
  164.  
  165.  
  166.  
  167.  
  168.  
  169. int32_t main() {
  170.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  171.  
  172.     int t = 1;
  173.     // cin >> t;
  174.     while (t--) {
  175.         solve();
  176.     }
  177.  
  178.     return 0;
  179. }
Success #stdin #stdout 0.01s 5292KB
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stdout
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17 , Followup => 13
https://ideone.com/nVEBdN
language:
C++14 (gcc 8.3)
created:
9 hours ago
visibility:
public

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