#1804. 【2017.3长乐省选集训Day2T2】字符串匹配

https://sjzezoj.com/submission/65996

S2OJ/1804/1804.cpp

@@ -0,0 +1,66 @@
+#include <iostream>
+#include <unordered_map>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int t, c;
+
+    cin >> t >> c;
+
+    while (t--) {
+        int n, m;
+
+        cin >> n >> m;
+
+        std::vector<int> s(1), t(1);
+        std::unordered_map<int, int> lst_s, lst_t;
+
+        for (int i = 1, x; i <= n; i++) {
+            cin >> x;
+
+            s.emplace_back(i - lst_s[x]);
+            lst_s[x] = i;
+        }
+
+        for (int i = 1, x; i <= m; i++) {
+            cin >> x;
+
+            t.emplace_back(i - lst_t[x]);
+            lst_t[x] = i;
+        }
+
+        std::vector<int> nxt(m + 1);
+
+        for (int i = 2, j = 0; i <= m; i++) {
+            while (j && t[j + 1] != std::min(t[i], j + 1)) j = nxt[j];
+            if (t[j + 1] == std::min(t[i], j + 1)) j++;
+            nxt[i] = j;
+        }
+
+        std::vector<int> ans;
+
+        for (int i = 1, j = 0; i <= n; i++) {
+            while (j && t[j + 1] != std::min(s[i], j + 1)) j = nxt[j];
+            if (std::min(s[i], j + 1) == t[j + 1]) j++;
+            if (j == m) {
+                ans.emplace_back(i - m + 1);
+                j = nxt[j];
+            }
+        }
+
+        cout << ans.size() << endl;
+
+        for (int x : ans) cout << x << ' ';
+
+        cout << endl;
+    }
+
+    return 0;
+}