atcoder/abc027B

Author: xirc

atcoder/abc027/B/main.cpp

@@ -0,0 +1,34 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = int64_t;
+using ff = long double;
+
+int N;
+vector<int> A;
+
+int solve() {
+    int M = accumulate(A.begin(), A.end(), 0, plus<int>());
+    if (M % N != 0) return -1;
+    M /= N;
+
+    int ans = 0;
+    int acc = 0;
+    for (auto ai : A) {
+        acc += ai - M;
+        if (acc != 0) ans += 1;
+    }
+    return ans;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    cin >> N;
+    A.assign(N, 0);
+    for (auto &ai : A) cin >> ai;
+    cout << solve() << endl;
+
+    return 0;
+}