hdu 5288 OO’s Sequence（two point + rmq）

题目链接：hdu 5288 OO’s Sequence

#include <cstdio>#include <cstring>#include <vector>#include <algorithm>using namespace std;const int maxn = 1e4 + 5;const int maxm = 1e5 + 5;const int mod = 1e9 + 7;int N, v[maxm], a[maxm], l[maxm], r[maxm];vector<int> G[maxn];void init () {for (int i = 1; i < maxn; i++) {for (int j = i; j < maxn; j += i)G[j].push_back(i);}}int main () {init();while (scanf("%d", &N) == 1) {memset(v, 0, sizeof(v));memset(l, 0, sizeof(l));for (int i = 1; i <= N; i++) {scanf("%d", &a[i]);for (int j = 0; j < G[a[i]].size(); j++) {l[i] = max(l[i], v[G[a[i]][j]]);}v[a[i]] = i;}int ans = 0;for (int i = 0; i <= N; i++)r[i] = v[i] = N + 1;for (int i = N; i; i--) {for (int j = 0; j < G[a[i]].size(); j++) {r[i] = min(r[i], v[G[a[i]][j]]);}v[a[i]] = i;ans = (ans + (i - l[i]) * (r[i] - i) % mod ) % mod;}printf("%d\n", ans);}return 0;}