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c_cpp
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#include <bits/stdc++.h> #define no "NO" #define yes "YES" #define F first #define S second #define vec vector #define task "main" #define ll long long #define _mp make_pair #define ii pair<int, int> #define sz(x) (int)x.size() #define all(x) x.begin(), x.end() #define evoid(val) return void(std::cout << val) #define FOR(i, a, b) for(int i = (a); i <= (b); ++i) #define FOD(i, b, a) for(int i = (b); i >= (a); --i) #define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin()) using namespace std; template<typename U, typename V> bool maximize(U &a, V b) { if (a < b) { a = b; return 1; } return 0; } template<typename U, typename V> bool minimize(U &a, V b) { if (a > b) { a = b; return 1; } return 0; } const int N = (int)2e5 + 9; const int INF = (int)1e9; const int MOD = (int)1e9 + 7; int n; int a[N]; ll ans = 0; int minVal[N], maxVal[N]; int sumMin[2], sumMax[2]; void solve(int l, int r) { int mid = (l + r) >> 1; minVal[mid + 1] = (int)1e9; maxVal[mid + 1] = 0; FOD(i, mid, l) { minVal[i] = min(minVal[i + 1], a[i]); maxVal[i] = max(maxVal[i + 1], a[i]); } FOR(i, mid + 1, r) { minVal[i] = min(minVal[i - 1], a[i]); maxVal[i] = max(maxVal[i - 1], a[i]); } // max and min on the left for (int i = mid, R = mid; i >= l; i--) { while (R < r && minVal[R + 1] >= minVal[i] && maxVal[R + 1] <= maxVal[i]) R++; if (minVal[R] >= minVal[i] && maxVal[R] <= maxVal[i]) if ((maxVal[i] - minVal[i]) % 2 == 0) ans += (R - mid + 1); } // max and min on the right for (int i = l, L = r, cnt = ((maxVal[L] - minVal[L]) % 2 == 0); i <= mid; i++) { while (L > mid && minVal[L - 1] < minVal[i] && maxVal[L - 1] > maxVal[i]) { L--; if ((maxVal[L] - minVal[L]) % 2 == 0) cnt++; } if (minVal[L] < minVal[i] && maxVal[L] > maxVal[i]) ans += cnt; } // max on the left, min on the right memset(sumMin, 0, sizeof(sumMin)); sumMin[(minVal[mid] % 2)]++; for (int i = mid, L = mid, R = mid; i >= l; i--) { while (R < r && minVal[R] >= minVal[i]) { R++; sumMin[minVal[R] % 2]++; } while (R < r && maxVal[R + 1] <= maxVal[i]) { R++; sumMin[minVal[R] % 2]++; } while (L < r && minVal[L] >= minVal[i]) { sumMin[minVal[L] % 2]--; L++; } if (minVal[L] < minVal[i] && maxVal[i] >= maxVal[R]) ans += sumMin[maxVal[i] % 2]; } // min on the left, max on the right memset(sumMax, 0, sizeof(sumMax)); sumMax[(minVal[mid] % 2)]++; for (int i = mid, L = mid, R = mid; i >= l; i--) { while (R < r && maxVal[R] <= maxVal[i]) { R++; sumMax[maxVal[R] % 2]++; } while (R < r && minVal[R + 1] >= minVal[i]) { R++; sumMax[maxVal[R] % 2]++; } while (L < r && maxVal[L] <= maxVal[i]) { sumMax[maxVal[L] % 2]--; L++; } if (minVal[L] >= minVal[i] && maxVal[i] < maxVal[R]) ans += sumMax[minVal[i] % 2]; } if (mid > l) solve(l, mid - 1); if (mid < r) solve(mid + 1, r); } void main_code() { cin >> n; FOR(i, 1, n) cin >> a[i]; solve(1, n); cout << ans; } int main() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); if (fopen(task".inp", "r")) { freopen(task".inp", "r", stdin); freopen(task".out", "w", stdout); } const bool MULTITEST = 0; int num_test = 1; if (MULTITEST) cin >> num_test; while (num_test--) { main_code(); cout << "\n"; } } /* Lak lu theo dieu nhac */
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