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- #include <bits/stdc++.h>
- using namespace std;
- struct RMQPM1 {
- vector<int> arr;
- vector<vector<int>> sparse;
- vector<vector<vector<int>>> precalc;
- vector<int> blockType;
- vector<int> logs;
- int n;
- int k;
- int blocks;
- int lg;
- const int INF = 1e9 + 7;
- RMQPM1(const vector<int>& inputArray) {
- arr = inputArray;
- n = arr.size();
- k = ceil(log2(n + 1) / 2);
- blocks = (n + k - 1) / k;
- lg = ceil(log2(blocks + 1));
- sparse.assign(lg, vector<int>(blocks, 0));
- precalc.assign((1 << (k - 1)), vector<vector<int>>(k, vector<int>(k + 1, 0)));
- blockType.assign(blocks, 0);
- logs.assign(blocks, 0);
- buildLogs();
- buildSparse();
- buildPrecalc();
- }
- void buildLogs() {
- logs[1] = 0;
- for (int i = 2; i < blocks; i++) {
- logs[i] = logs[i >> 1] + 1;
- }
- }
- void buildSparse() {
- for (int block = 0; block < blocks; block++) {
- int l = block * k;
- int r = min(l + k, n);
- int blockMin = arr[l];
- for (int i = l + 1; i < r; i++) {
- blockMin = min(blockMin, arr[i]);
- if (arr[i] == arr[i - 1] + 1) {
- blockType[block] |= (1 << (i - l - 1));
- }
- }
- sparse[0][block] = blockMin;
- }
- for (int bit = 1; bit < lg; bit++) {
- for (int i = 0; i + (1 << bit) <= blocks; i++) {
- sparse[bit][i] = min(sparse[bit - 1][i], sparse[bit - 1][i + (1 << (bit - 1))]);
- }
- }
- }
- void buildPrecalc() {
- for (int mask = 0; mask < (1 << (k - 1)); mask++) {
- for (int l = 0; l < k; l++) {
- precalc[mask][l][l] = INF;
- int curval = 0;
- for (int r = l; r < k; r++) {
- precalc[mask][l][r + 1] = min(precalc[mask][l][r], curval);
- if ((mask >> r) & 1) {
- curval++;
- } else {
- curval--;
- }
- }
- }
- }
- }
- int findShort(int left, int right) { // left and right are in one block
- int block = left / k;
- int ans = precalc[blockType[block]][left - block * k][right - block * k] + arr[left];
- return ans;
- }
- int findLong(int lblock, int rblock) {
- if (lblock == rblock) {
- return INF;
- }
- int bit = logs[rblock - lblock];
- int ans = min(sparse[bit][lblock], sparse[bit][rblock - (1 << bit)]);
- return ans;
- }
- int findMin(int left, int right) { // [left; right)
- int lblock = left / k;
- int rblock = right / k;
- if (lblock == rblock) {
- return findShort(left, right);
- } else {
- return min(findLong(lblock + 1, rblock), min(findShort(left, (lblock + 1) * k), findShort(rblock * k, right)));
- }
- }
- };
- int main() {
- int n;
- cin >> n;
- vector<int> arr(n);
- for (int& elem : arr) {
- cin >> elem;
- }
- RMQPM1 rmq(arr);
- int q;
- cin >> q;
- for (int i = 0; i < q; i++) {
- int left, right;
- cin >> left >> right;
- left--; // 0-indexing and half-intervals
- cout << rmq.findMin(left, right) << '\n';
- }
- return 0;
- }
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