Submission #1691943

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Source Code Expand

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <deque>
using namespace std;

#define iter(i, n) for (int i = 1; i <= n; ++i)
#define iter0(i, n) for (int i = 0; i < n; ++i)
#define iter_r(i, n) for (int i = n; i >= 1; --i)

const int NR = 1e6 + 10;

deque<int> q;
int L[NR], R[NR], n;
char s[NR], t[NR];

int main() {
	scanf("%d%s%s", &n, s + 1, t + 1);

	if (strcmp(s + 1, t + 1) == 0) {
		puts("0"); return 0;
	}


	int j = n;

	iter_r(i, n) {
		while (j > 0 && (j > i || s[j] != t[i])) --j;
		if (j == 0) { puts("-1"); return 0; }
		
		L[j] = i;
		if (R[j] == 0) R[j] = i;
	}
	
	//iter(i, n) printf("[%d %d] ", L[i], R[i]); puts("");

	int ans = 0, tag = 0; bool inited = false;
	iter_r(i, n) if (L[i] != 0) {
		if (!inited) {
			inited = true;
			q.push_back(i);
			q.push_back(L[i]);
		} else {
			int cnt = 1;
			while (!q.empty() && q.back() - tag - 1 >= L[i]) {
				if (q.back() - tag - 1 < R[i]) ++cnt;
				q.pop_back();
			}
			++tag;
			iter(k, cnt) q.push_back(L[i] + tag);
			q.push_front(i + tag);
			
		}
	//	for (int pos : q) printf("%d ", pos - tag); puts("");
		ans = max(ans, (int) q.size() - 1);
	}
	printf("%d\n", ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:18:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%s%s", &n, s + 1, t + 1);
                                   ^

Judge Result