Add: Problem 1015

src/1015/main.cpp

@@ -0,0 +1,60 @@
+#include <iostream>
+#include <vector>
+#include <cstdio>
+#include <cstring>
+using namespace std;
+
+vector<int> compute(string p);
+int kmp(string, string);
+
+int main() {
+ int num;
+ cin >> num;
+ for (int i = 0; i < num; i++) {
+ string a;
+ string p;
+ cin >> p;
+ cin >> a;
+ cout << kmp(a,p) << endl;
+ }
+ return 0;
+}
+
+vector<int> compute(string p) {
+ int pl = p.length();
+ vector<int> next(pl+1, 0);
+ for (int i = 1; i < pl; i++) {
+ int j = i;
+ while (j > 0) {
+ j = next[j];
+ if (p[j] == p[i]) {
+ next[i+1] = j + 1;
+ break;
+ }
+ }
+ }
+ return next;
+}
+
+int kmp(string a, string p) {
+ int ans = 0;
+ int al = a.length();
+ int pl = p.length();
+ vector<int> next;
+ next = compute(p);
+
+ for (int i = 0, j = 0; i < al; i++) {
+ if (j < pl && a[i] == p[j]) j++;
+ else {
+ while (j > 0) {
+ j = next[j];
+ if (a[i] == p[j]) {
+ j++;
+ break;
+ }
+ }
+ }
+ if (j == pl) ans++;
+ }
+ return ans;
+}