POJ 2328 解题报告

这道题我是用segment tree做的。刚开始TLE，后来把cin, cout改成scanf, printf后就过了。

2823Accepted42344K6641MSC++3335B

/* ID: thestor1 LANG: C++ TASK: poj2823 */#include <iostream>#include <fstream>#include <cmath>#include <cstdio>#include <cstring>#include <limits>#include <string>#include <vector>#include <list>#include <set>#include <map>#include <queue>#include <stack>#include <algorithm>#include <cassert>using namespace std;void build(std::vector<pair<int, int> > &segmentTree, int left, int right, int index, std::vector<int> &nums){if (left != right){int mid = left + ((right - left) >> 1);build(segmentTree, left, mid, 2 * index + 1, nums);build(segmentTree, mid + 1, right, 2 * index + 2, nums);segmentTree[index].first = min(segmentTree[2 * index + 1].first, segmentTree[2 * index + 2].first);segmentTree[index].second = max(segmentTree[2 * index + 1].second, segmentTree[2 * index + 2].second);}else{// cout << "[build]index: " << index << ", left: " << left << ", nums[left]: " << nums[left] << endl;segmentTree[index].first = segmentTree[index].second = nums[left];}}void query(std::vector<pair<int, int> > &segmentTree, int left, int right, int index, int lindex, int rindex, pair<int, int> &minmax){if (lindex <= left && right <= rindex){minmax.first = min(minmax.first, segmentTree[index].first);minmax.second = max(minmax.second, segmentTree[index].second);return;}if (left != right){int mid = left + ((right - left) >> 1);if (rindex <= mid){query(segmentTree, left, mid, 2 * index + 1, lindex, rindex, minmax);}else if (mid + 1 <= lindex){query(segmentTree, mid + 1, right, 2 * index + 2, lindex, rindex, minmax);}else{query(segmentTree, left, mid, 2 * index + 1, lindex, rindex, minmax);query(segmentTree, mid + 1, right, 2 * index + 2, lindex, rindex, minmax);}}}void printSegmentTree(std::vector<pair<int, int> > &segmentTree, int left, int right, int index){cout << "index: " << index << " (" << segmentTree[index].first << ", " << segmentTree[index].second << ")" << endl;if (left != right){int mid = left + ((right - left) >> 1);printSegmentTree(segmentTree, left, mid, 2 * index + 1);printSegmentTree(segmentTree, mid + 1, right, 2 * index + 2);}}int main(){// std::ios::sync_with_stdio(false);int n, k;// cin >> n >> k;scanf("%d%d", &n, &k);std::vector<int> nums(n);for (int i = 0; i < n; ++i){// cin >> nums[i];scanf("%d", &nums[i]);}// cout << "nums:" << endl;// for (int i = 0; i < n; ++i)// {// cout << nums[i] << " ";// }// cout << endl;std::vector<pair<int, int> > segmentTree(4 * n);build(segmentTree, 0, n - 1, 0, nums);// printSegmentTree(segmentTree, 0, n - 1, 0);std::vector<pair<int, int > > minmaxs(n - k + 2, make_pair(INT_MAX, INT_MIN));for (int i = 0; i + k - 1 < n; ++i){// i, i + k - 1;query(segmentTree, 0, n - 1, 0, i, i + k - 1, minmaxs[i]);}for (int i = 0; i + k - 1 < n; ++i){// cout << minmaxs[i].first << " ";printf("%d ", minmaxs[i].first);}// cout << endl;printf("\n");for (int i = 0; i + k - 1 < n; ++i){// cout << minmaxs[i].first << " ";printf("%d ", minmaxs[i].second);}// cout << endl;printf("\n");return 0;  }