题目
思路
- 交错和
代码
ini
复制代码
onst int N = 3e5+10; int v[N]; void solve() { int n;cin >> n; for (int i = 1; i<=n; i++){ cin >> v[i]; if (i%2 == 0){ v[i]*=-1; } } map<long long, long long> mp; mp[0] = 1; long long ans = 0; long long suma = 0; for (int i = 1; i<=n; i++){ suma+=v[i]; ans+=mp[suma]; mp[suma]++; } cout << ans; }
