C++ N个Boost区间的组合
我有一个服务,它在4个不同的位置有停机。我正在将每个位置的停机建模为一个Boost ICL interval_集合。我想知道至少N个位置何时有活动停机 因此,下面,我实现了一个组合算法,这样我就可以通过区间集交点在元素集之间创建组合 当这个过程结束时,我应该设置一定数量的间隔,每个间隔同时定义N个位置的中断,最后一步将加入它们以获得所需的完整画面 问题是我目前正在调试代码,当打印每个交叉点的时间到来时,输出文本变得疯狂(即使我使用gdb一步一步地调试),我看不到它们,导致大量CPU使用 我猜,不知怎么的,我发送的输出内存比我应该的要大,但我看不出问题出在哪里 这是一个SSCCE:C++ N个Boost区间的组合,c++,algorithm,boost,intervals,boost-icl,C++,Algorithm,Boost,Intervals,Boost Icl,我有一个服务,它在4个不同的位置有停机。我正在将每个位置的停机建模为一个Boost ICL interval_集合。我想知道至少N个位置何时有活动停机 因此,下面,我实现了一个组合算法,这样我就可以通过区间集交点在元素集之间创建组合 当这个过程结束时,我应该设置一定数量的间隔,每个间隔同时定义N个位置的中断,最后一步将加入它们以获得所需的完整画面 问题是我目前正在调试代码,当打印每个交叉点的时间到来时,输出文本变得疯狂(即使我使用gdb一步一步地调试),我看不到它们,导致大量CPU使用 我猜,不
#include <boost/icl/interval_set.hpp>
#include <algorithm>
#include <iostream>
#include <vector>
int main() {
// Initializing data for test
std::vector<boost::icl::interval_set<unsigned int> > outagesPerLocation;
for(unsigned int j=0; j<4; j++){
boost::icl::interval_set<unsigned int> outages;
for(unsigned int i=0; i<5; i++){
outages += boost::icl::discrete_interval<unsigned int>::closed(
(i*10), ((i*10) + 5 - j));
}
std::cout << "[Location " << (j+1) << "] " << outages << std::endl;
outagesPerLocation.push_back(outages);
}
// So now we have a vector of interval_sets, one per location. We will combine
// them so we get an interval_set defined for those periods where at least
// 2 locations have an outage (N)
unsigned int simultaneusOutagesRequired = 2; // (N)
// Create a bool vector in order to filter permutations, and only get
// the sorted permutations (which equals the combinations)
std::vector<bool> auxVector(outagesPerLocation.size());
std::fill(auxVector.begin() + simultaneusOutagesRequired, auxVector.end(), true);
// Create a vector where combinations will be stored
std::vector<boost::icl::interval_set<unsigned int> > combinations;
// Get all the combinations of N elements
unsigned int numCombinations = 0;
do{
bool firstElementSet = false;
for(unsigned int i=0; i<auxVector.size(); i++){
if(!auxVector[i]){
if(!firstElementSet){
// First location, insert to combinations vector
combinations.push_back(outagesPerLocation[i]);
firstElementSet = true;
}
else{
// Intersect with the other locations
combinations[numCombinations] -= outagesPerLocation[i];
}
}
}
numCombinations++;
std::cout << "[-INTERSEC-] " << combinations[numCombinations] << std::endl; // The problem appears here
}
while(std::next_permutation(auxVector.begin(), auxVector.end()));
// Get the union of the intersections and see the results
boost::icl::interval_set<unsigned int> finalOutages;
for(std::vector<boost::icl::interval_set<unsigned int> >::iterator
it = combinations.begin(); it != combinations.end(); it++){
finalOutages += *it;
}
std::cout << finalOutages << std::endl;
return 0;
}
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int main(){
//初始化测试数据
std::矢量输出位置;
对于置换循环末尾的(unsigned int j=0;j),您可以编写:
numCombinations++;
std::cout << "[-INTERSEC-] " << combinations[numCombinations] << std::endl; // The problem appears here
或者,对于c++03
std::cout << "[-INTERSEC-] " << combinations[combinations.size()-1] << "\n";
std::coutAs,这里有一种“高级”方法
Boost ICL容器不仅仅是“美化的间隔起点/终点对”的容器。它们旨在以一种通用优化的方式实现组合、搜索的业务
所以你不必这么做。
如果你让图书馆做它应该做的事:
using TimePoint = unsigned;
using DownTimes = boost::icl::interval_set<TimePoint>;
using Interval = DownTimes::interval_type;
using Records = std::vector<DownTimes>;
好的,让我们进行筛选。我们只需要在下行图上工作的谓词,对吗
// define threshold where at least 2 locations have an outage
auto exceeds_threshold = [](DownMap::value_type const& slot) {
return slot.second >= 2;
};
合并时隙
事实上。我们只是创建了另一个停机时间集,对吧。只是,这次不是每个位置
数据结构的选择再次赢得了胜利:
// just printing the union of any criticals:
DownTimes merged;
for (auto&& slot : tallied | filtered(exceeds_threshold) | map_keys)
merged.insert(slot);
报告
std::cout << "Criticals: " << merged << "\n";
// We will do a tally of affected locations per time slot
DownMap tallied;
for (auto& location : records)
for (auto& incident : location)
tallied.add({incident, 1u});
// define threshold where at least 2 locations have an outage
auto exceeds_threshold = [](DownMap::value_type const& slot) {
return slot.second >= 2;
};
// just printing the union of any criticals:
DownTimes merged;
for (auto&& slot : tallied | filtered(exceeds_threshold) | map_keys)
merged.insert(slot);
std::cout << "Criticals: " << merged << "\n";
#include <boost/icl/interval_set.hpp>
#include <boost/icl/interval_map.hpp>
#include <boost/range.hpp>
#include <boost/range/algorithm.hpp>
#include <boost/range/adaptors.hpp>
#include <boost/range/numeric.hpp>
#include <boost/range/irange.hpp>
#include <algorithm>
#include <iostream>
#include <vector>
using TimePoint = unsigned;
using DownTimes = boost::icl::interval_set<TimePoint>;
using Interval = DownTimes::interval_type;
using Records = std::vector<DownTimes>;
using Tally = unsigned; // or: bit mask representing affected locations?
using DownMap = boost::icl::interval_map<TimePoint, Tally>;
// Just for fun, removed the explicit loops from the generation too. Obviously,
// this is bit gratuitous :)
static DownTimes generate_downtime(int j) {
return boost::accumulate(
boost::irange(0, 5),
DownTimes{},
[j](DownTimes accum, int i) { return accum + Interval::closed((i*10), ((i*10) + 5 - j)); }
);
}
int main() {
// Initializing data for test
using namespace boost::adaptors;
auto const records = boost::copy_range<Records>(boost::irange(0,4) | transformed(generate_downtime));
for (auto location : records | indexed()) {
std::cout << "Location " << (location.index()+1) << " " << location.value() << std::endl;
}
// We will do a tally of affected locations per time slot
DownMap tallied;
for (auto& location : records)
for (auto& incident : location)
tallied.add({incident, 1u});
// We will combine them so we get an interval_set defined for those periods
// where at least 2 locations have an outage
auto exceeds_threshold = [](DownMap::value_type const& slot) {
return slot.second >= 2;
};
// just printing the union of any criticals:
DownTimes merged;
for (auto&& slot : tallied | filtered(exceeds_threshold) | map_keys)
merged.insert(slot);
std::cout << "Criticals: " << merged << "\n";
}
Location 1 {[0,5][10,15][20,25][30,35][40,45]}
Location 2 {[0,4][10,14][20,24][30,34][40,44]}
Location 3 {[0,3][10,13][20,23][30,33][40,43]}
Location 4 {[0,2][10,12][20,22][30,32][40,42]}
Criticals: {[0,4][10,14][20,24][30,34][40,44]}