fork download 
  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.  
  27.  
  28. int consistency(int n) {
  29.  
  30. 	int s = 0, e = n-1;
  31. 	int p1 = 0, p2 = 0;
  32.  
  33. 	bool isReversed = false;
  34. 	int turn = 1; //* a's turn 
  35.  
  36. 	while(s<=e){
  37. 		int ele = -1;
  38. 		if(isReversed){
  39. 			//* Consume from end
  40. 			ele = a[e];
  41. 			e--;
  42. 		}
  43. 		else{
  44. 			//* Consume normal i.e. from s
  45. 			ele = a[s];
  46. 			s++;
  47. 		}
  48.  
  49. 		if(!(ele & 1)){
  50. 			isReversed = !isReversed;
  51. 		}
  52. 		if(turn) p1 += ele;
  53. 		else p2 += ele;
  54. 		turn ^= 1;
  55. 	}
  56.  
  57. 	return  p1 - p2;
  58.  
  59. }
  60.  
  61.  
  62.  
  63.  
  64.  
  65.  
  66.  
  67.  
  68.  
  69.  
  70.  
  71.  
  72. int practice(int n) {
  73.  
  74. 	int s = 0, e = n-1;
  75. 	bool turn = 1;
  76. 	bool isRev = false;
  77.  
  78. 	int p1 = 0, p2 = 0;
  79.  
  80. 	while(s<=e){
  81.  
  82. 		int val = -1;
  83. 		if(isRev){
  84. 			val = a[e];
  85. 			e--;
  86. 		}
  87. 		else {
  88. 			val = a[s];
  89. 			s++;
  90. 		}
  91.  
  92. 		if(!(val&1)){
  93. 			isRev = !isRev;
  94. 		}
  95.  
  96. 		if(turn){
  97. 			p1 += val;
  98. 		}
  99. 		else p2 += val;
  100.  
  101. 		turn ^= 1;
  102.  
  103.  
  104. 	}
  105.  
  106. 	return p1-p2;
  107.  
  108. }
  109.  
  110.  
  111.  
  112. void solve() {
  113.  
  114.     int n;
  115.     cin >> n;
  116.  
  117.     a.resize(n);
  118.     for(int i=0; i<n; i++) cin >> a[i];
  119.  
  120.     // cout << consistency(n) << endl;
  121.  
  122.  
  123.     cout << consistency(n) << " -> " << practice(n) << endl;
  124.  
  125. }
  126.  
  127.  
  128.  
  129.  
  130.  
  131. int32_t main() {
  132.     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  133.  
  134.     int t = 1;
  135.     while (t--) {
  136.         solve();
  137.     }
  138.  
  139.     return 0;
  140. }
Success #stdin #stdout 0.01s 5324KB
comments (?)
stdin 
4
2 1 4 3
stdout 
2 -> 2
https://ideone.com/wK9iOH
language:
C++14 (gcc 8.3)
created:
3 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!