#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include <cmath>
#define MAXN 110000
#define QWQ cout << "qwq" << endl;
using namespace std;
int n, m, cnt;
int a[MAXN + 10], qaq[MAXN + 10];
int pl[MAXN + 10], pr[MAXN + 10], cl[MAXN + 10], len;
int c[MAXN + 10];
int f[1000 + 10][1000 + 10][2];
vector <int> vec[MAXN + 10];
int big, gib;
int finding(int l, int r, int x) {
return upper_bound(vec[x].begin(), vec[x].end(), r) - lower_bound(vec[x].begin(), vec[x].end(), l);
}
void Three_Flower() {
for(int p = 1; p <= n; p++) qaq[p] = a[p];
sort(qaq + 1, qaq + n + 1);
cnt = unique(qaq + 1, qaq + n + 1) - qaq - 1;
for(int p = 1; p <= n; p++)
a[p] = lower_bound(qaq + 1, qaq + cnt + 1, a[p]) - qaq;
}
void qwq(int l, int r, int num) {
int cnt = finding(l, r, num);
if(cnt > big || (cnt == big && num < gib)) {
big = cnt;
gib = num;
}
}
int solve(int l, int r) {
int L = cl[l], R = cl[r];
int x = 0, y = 0;
if(L + 1 <= R - 1) x = L + 1, y = R - 1;
big = f[x][y][0], gib = f[x][y][1];
if(L == R)
for(int p = l; p <= r; p++) qwq(l, r, a[p]);
else {
for(int p = l; p <= pr[L]; p++) qwq(l, r, a[p]);
for(int p = pl[R]; p <= r; p++) qwq(l, r, a[p]);
}
return qaq[gib];
}
void block() {
len = sqrt(log(n) / log(2) * n);
for(int p = 1; p <= ceil(n * 1.0 / len); p++) {
pl[p] = (p - 1)* len + 1;
pr[p] = p * len;
}
for(int p = 1; p <= n; p++)
cl[p] = (p - 1) / len + 1;
for(int p = 1; p <= ceil(n * 1.0 / len); p++)
for(int i = p; i <= ceil(n * 1.0 / len); i++) {
memset(c, 0, sizeof(c));
for(int j = pl[p]; j <= pr[i]; j++) c[a[j]]++;
for(int j = 1; j <= cnt; j++)
if(c[j] > f[p][i][0] || (c[j] == f[p][i][0] && j < f[p][i][1]))
f[p][i][0] = c[j], f[p][i][1] = j;
}
}
int main() {
scanf("%d%d", &n, &m);
for(int p = 1; p <= n; p++) scanf("%d", &a[p]);
Three_Flower();
for(int p = 1; p <= n; p++) vec[a[p]].push_back(p);
block();
int last = 0;
while(m--) {
int x, y;
scanf("%d%d", &x, &y);
x = (x + last - 1) % n + 1, y = (y + last - 1) % n + 1;
if(x > y) swap(x, y);
last = solve(x, y);
printf("%d\n", last);
}
}
思路是 https://www.luogu.com.cn/blog/user5912/solution-p4168
就是 lyd 巨佬在书上写的第二种方法,然后 T 了一个点 QAQ,求助