P1360 [USACO07MAR]Gold Balanced Lineup G

https://www.luogu.com.cn/record/87243916

Luogu/P1360/P1360.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+#include <algorithm>
+#include <map>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int n, m, ans;
+std::map<std::vector<int>, int> map;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    std::vector<int> s(m);
+
+    map[s] = 0;
+    for (int i = 1, x; i <= n; i++) {
+        cin >> x;
+
+        for (int j = 0; j < m; j++) {
+            if (x >> j & 1) s[j]++;
+        }
+
+        if (!std::count(s.begin(), s.end(), 0)) {
+            for (int& x : s) x--;
+        }
+
+        if (map.count(s)) {
+            ans = std::max(ans, i - map[s]);
+        } else {
+            map[s] = i;
+        }
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}