Upload Codes: AtCoder ABC 395

AtCoder/abc395/C_Shortest_Duplicate_Subarray.cpp

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+#include <bits/stdc++.h>
+#define lo long long
+#define INF INT_MAX
+#define LLM LONG_LONG_MAX
+#define endl "\n"
+
+using namespace std;
+/*
+    toothless. #17
+    @fredcss_dev
+*/
+
+int wczffl_503(int N, vector<int>& A) {
+    for (int i = 0; i < N - 1; ++i) {
+        if (A[i] == A[i + 1]) {
+            return 2;
+        }
+    }
+    unordered_map<int, vector<int>> pos;
+    for (int i = 0; i < N; ++i) {
+        pos[A[i]].push_back(i);
+    }
+    int mn = INT_MAX;
+    for (const auto& entry : pos) {
+        const vector<int>& vt = entry.second;
+        if (vt.size() < 2) continue;
+        
+        for (size_t i = 0; i < vt.size() - 1; ++i) {
+            int now = vt[i + 1] - vt[i] + 1;
+            if (now < mn) {
+                mn = now;
+            }
+        }
+    }
+    return (mn != INT_MAX) ? mn : -1;
+}
+
+int N;
+
+signed main() {
+    cin >> N;
+    vector<int> A(N);
+    for (int i = 0; i < N; ++i) {
+        cin >> A[i];
+    }
+    int res = wczffl_503(N, A);
+    cout << res;
+    return 0;
+}