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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. inline int power(int a, int b) {
  6.     int x = 1;
  7.     while (b) {
  8.         if (b & 1) x *= a;
  9.         a *= a;
  10.         b >>= 1;
  11.     }
  12.     return x;
  13. }
  14.  
  15.  
  16. const int M = 1000000007;
  17. const int N = 3e5+9;
  18. const int INF = 2e9+1;
  19. const int LINF = 2000000000000000001;
  20.  
  21. //_ ***************************** START Below *******************************
  22.  
  23.  
  24.  
  25. vector<int> a;
  26. void consistency1(int n, int k) {
  27.  
  28. 	int  s= 0, e = n-1;
  29. 	int ans = 0;
  30.  
  31. 	//* keep in mind  s<e   (Not s<=e )
  32. 	while(s<e){
  33. 		int sum = a[s] + a[e];
  34. 		if(sum > k){
  35. 			e--;
  36. 		}
  37. 		else{
  38. 			ans += (e-s);
  39. 			s++;
  40. 		}
  41. 	}
  42.  
  43. 	cout << ans << " ";
  44.  
  45. }
  46.  
  47.  
  48. //* Template 2 : 
  49. //* Shrink invalid window (if it can be)
  50. //* 	Invalid window => sum > k   
  51. //* 	Valid window   =>  sum <= k
  52.  
  53. void consistency2(int n, int k) {
  54.  
  55. 	int  s = 0, e = n-1;
  56. 	int ans = 0;
  57.  
  58. 	while(s<n){
  59. 		int sum = a[s] + a[e];
  60.  
  61. 		while(e>s && sum>k){
  62. 			e--;
  63. 			sum = a[s] + a[e];
  64. 		}
  65.  
  66. 		if(e == s)  break;
  67.  
  68. 		ans += (e-s);
  69. 		s++;
  70. 	}
  71.  
  72. 	cout << ans << " ";
  73.  
  74. }
  75.  
  76.  
  77. void solve() {
  78.  
  79. 	int n, k;
  80. 	cin >> n >> k;
  81.  
  82. 	a.resize(n);
  83.  
  84. 	for(int i=0; i<n; i++) cin >> a[i];
  85.  
  86.     consistency1(n, k);
  87.     consistency2(n, k);
  88.  
  89. }
  90.  
  91.  
  92.  
  93.  
  94.  
  95. int32_t main() {
  96.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  97.  
  98.     int t = 1;
  99.     // cin >> t;
  100.     while (t--) {
  101.         solve();
  102.     }
  103.  
  104.     return 0;
  105. }
Success #stdin #stdout 0s 5324KB
comments (?)
stdin 
5 16
1 5 10 15 20
stdout 
4 4
https://ideone.com/Bdqw9Y
language:
C++14 (gcc 8.3)
created:
2 days ago
visibility:
public

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