672C1_Pokémon Army (easy version).cpp

800 Codeforces Solutions/672C1_Pokémon Army (easy version).cpp

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+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+inline int64_t calc(const vector<int> &a) {
+	int n = a.size();
+	vector<int64_t> d1(n+1), d2(n+1);
+	d1[0] = -static_cast<int64_t>(1e18);
+	d2[0] = 0;
+	for (int i = 0; i < n; ++i) {
+		d1[i+1] = max(d1[i], d2[i] + a[i]);
+		d2[i+1] = max(d2[i], d1[i] - a[i]);
+	}
+	return max(d1.back(), d2.back());
+}
+
+int main() {
+	ios_base::sync_with_stdio(false);
+	int t; cin >> t;
+	while (t--) {
+		int n, q; cin >> n >> q;
+		vector<int> a(n);
+		for (int i = 0; i < n; ++i) {
+			cin >> a[i];
+		}
+		cout << calc(a) << "\n";
+		for (int i = 0; i < q; ++i) {
+			int l, r; cin >> l >> r; --l; --r;
+			swap(a[l], a[r]);
+			cout << calc(a) << "\n";
+		}
+	}
+	return 0;
+}