(模板)后缀数组（lcp和rmq）

char s[mxn];
int sa[mxn], t[mxn], t2[mxn], c[mxn], f[mxn][20], ft[mxn];
int Rank[mxn], height[mxn];

void get_sa(int m, int n) { //n = strlen(s) + 1;
	int i, *x = t, *y = t2;
	for(i = 0; i < m; ++i) c[i] = 0;
	for(i = 0; i < n; ++i) ++c[x[i]=s[i]];
	for(i = 1; i < m; ++i) c[i] += c[i-1];
	for(i = n - 1; i >= 0; --i) sa[--c[x[i]]] = i;
	for(int k = 1; k <= n; k <<= 1) {
		int p = 0;
		for(i = n - k; i < n; ++i) y[p++] = i;
		for(i = 0; i < n; ++i) if(sa[i] >= k) y[p++] = sa[i] - k;
		for(i = 0; i < m; ++i) c[i] = 0;
		for(i = 0; i < n; ++i) c[x[y[i]]] ++;
		for(i = 1; i < m; ++i) c[i] += c[i-1];
		for(i = n - 1; i >= 0; --i) sa[--c[x[y[i]]]] = y[i];
		swap(x, y);
		p = 1, x[sa[0]] = 0;
		for(i = 1; i < n; ++i)
			x[sa[i]] = y[sa[i-1]] == y[sa[i]] && y[sa[i-1]+k] == y[sa[i]+k] ?p - 1: p ++;
		if(p >= n) break;
		m = p;
	}
}
void get_h(int n) {
	int i, j, k = 0;
	for(i = 1; i <= n; ++i) Rank[sa[i]] = i;
	for(i = 0; i < n; ++i) {
		if(k) --k;
		j = sa[Rank[i]-1];
		while(s[i+k] == s[j+k]) ++k;
		height[Rank[i]] = k;
	}
}
void rmq(int n) {
	for(int i = 0; i < mxn; ++i)
		ft[i] = (int)(log(i * 1.0) / log(2.0));
	for(int i = 1; i <= n; ++i) f[i][0] = height[i];
	for(int j = 1; j < 20; ++j)
		for(int i =1; i + (1 << j) - 1 <= n; ++i)
			f[i][j] = min(f[i][j-1], f[i+(1<<j-1)][j-1]);
}
int lcp(int a, int b) {
	int x = Rank[a], y = Rank[b];
	if(x > y) swap(x, y); ++x;
	int t = ft[y-x+1];
	return min(f[x][t], f[y-(1<<t)+1][t]);
}