[洛谷P2408]不同子串个数

题目大意：给你一个字符串，求其中本质不同的字串的个数

题解：同[洛谷P4070][SDOI2016]生成魔咒，只要最后再输出就行了

卡点：无

 

C++ Code：

#include <cstdio>
#include <map>
#define maxn 100010
long long ans;
namespace SAM {
#define N (maxn << 1)
#define root 1
	int R[N], fail[N];
	int nxt[N][26];
	int lst = root, idx = root;
	void append(char __ch) {
		int ch = __ch - 'a';
		int p = lst, np = lst = ++idx;
		R[np] = R[p] + 1;
		for (; p && !nxt[p][ch]; p = fail[p]) nxt[p][ch] = np;
		if (!p) fail[np] = root;
		else {
			int q = nxt[p][ch];
			if (R[p] + 1 == R[q]) fail[np] = q;
			else {
				int nq = ++idx;
				std::copy(nxt[q], nxt[q] + 26, nxt[nq]);
				fail[nq] = fail[q], R[nq] = R[p] + 1, fail[np] = fail[q] = nq;
				for (; p && nxt[p][ch] && nxt[p][ch] == q; p = fail[p]) nxt[p][ch] = nq;
			}
		}
	}
	int query() {
		return R[lst] - R[fail[lst]];
	}
#undef root
#undef N
}

#define maxn 100010
int n;
char s[maxn];
int main() {
	scanf("%d%s", &n, s);
	for (int i = 0; i < n; i++) {
		SAM::append(s[i]);
		ans += SAM::query();
	}
	printf("%lld\n", ans);
	return 0;
}