我正在尝试计算 vector vector 中一系列元素的能量。一旦特定元素具有合适的能量,它就会被插入另一个 vector vector 中。这是一个例子,因为它很难解释:
bool energy(const std::vector<double> &vals)
{
float sum = 0.0;
for(unsigned i=0; (i < vals.size()); i++)
{
sum += (vals[i]*vals[i]);
}
//cout << sum << endl;
return (sum >= 5);
}
int main(int argc, char *argv[]) {
std::vector<vector<double> > vals {
{0, 0, 0, 0, 0}, // This has an energy of "0" -> does not count
{1, 1, 1, 1, 1}, // This has an energy of "5" -> push_back to vector[0]
{1, 1, 1, 1, 1}, // This has an energy of "5" -> push_back to vector[0]
{1, 1, 1, 1, 1}, // This has an energy of "5" -> push_back to vector[0]
{1, 2, 1, 1, 1}, //This has an energy of "5" -> push_back to vector[0]
{0, 0, 0, 0, 0}, // This has an energy of "0" -> does not count && start a new
// vector
{1, 2, 3, 4, 5}, // This has an energy of "55" -> push_back to vector[1]
{1, 2, 3, 4, 5}, // This has an energy of "55" -> push_back to vector[1]
{1, 2, 3, 4, 5}, // This has an energy of "55" -> push_back to vector[1]
{1, 2, 3, 4, 5} // This has an energy of "55" -> push_back to vector[1]
};
std::vector<vector<double> > clusters;
std::vector<vector<double> > tmp;
//std::for_each(vals.begin(), vals.end(), energy);
int j = 0;
for(unsigned i=0; (i < vals.size()); i++)
{
if(energy(vals[i]))
{
clusters.resize(j + 1);
clusters[j] = vals[i];
}else if(!energy(vals[i]) && energy(vals[i+1]))
{
j++;
}
}
for(unsigned i=0; (i < clusters.size()); i++)
{
for(unsigned j=0; (j < clusters[i].size()); j++)
{
cout << clusters[i][j] << ' ';
}
cout << endl;
}
}
应该发生什么
应该有2
名为 clusters
的 vector 的 vector 元素每个包含值:
clusters[0] = {
1, 1, 1, 1, 1,
1, 1, 1, 1, 1,
1, 1, 1, 1, 1,
1, 2, 1, 1, 1
};
`clusters[1] = 1, 2, 3, 4, 5,
1, 2, 3, 4, 5,
1, 2, 3, 4, 5,
1, 2, 3, 4, 5}`
发生了什么?
vector 的 vector 似乎覆盖了插入其中的 block 。因此,我只是得到它找到的最后一个元素,而不是上面的内容:
`cluster[0] = {1 2 1 1 1}
cluster[1] = {1 2 3 4 5}`
我的想法和尝试是将每个“ block ”存储在包含足够能量的 vector vector 中,然后将所有这些值放入 vector<double>
中。然后将这个 vector 插入簇 block 中..
是否有替代方法,更简单的解决此问题的方法?
最佳答案
更正后的代码:
#include<vector>
#include<iostream>
using namespace std;
bool energy(const std::vector<double> &vals)
{
float sum = 0.0;
for(unsigned i=0; (i < vals.size()); i++)
{
sum += (vals[i]*vals[i]);
}
//cout << sum << endl;
return (sum >= 5);
}
int main(int argc, char *argv[]) {
std::vector<vector<double> > vals {
{0, 0, 0, 0, 0}, // This has an energy of "0" -> does not count
{1, 1, 1, 1, 1}, // This has an energy of "5" -> push_back to vector[0]
{1, 1, 1, 1, 1}, // This has an energy of "5" -> push_back to vector[0]
{1, 1, 1, 1, 1}, // This has an energy of "5" -> push_back to vector[0]
{1, 2, 1, 1, 1}, //This has an energy of "5" -> push_back to vector[0]
{0, 0, 0, 0, 0}, // This has an energy of "0" -> does not count && start a new
// vector
{1, 2, 3, 4, 5}, // This has an energy of "55" -> push_back to vector[1]
{1, 2, 3, 4, 5}, // This has an energy of "55" -> push_back to vector[1]
{1, 2, 3, 4, 5}, // This has an energy of "55" -> push_back to vector[1]
{1, 2, 3, 4, 5} // This has an energy of "55" -> push_back to vector[1]
};
std::vector<vector<double> > tmp(vals.size());
std::vector<vector<double> > clusters(vals.size());
int j = 0;
for(unsigned i=0; (i < vals.size()); i++)
{
if(energy(vals[i]))
{
clusters[j].insert(clusters[j].end(), vals[i].begin(), vals[i].end());
}else if(!energy(vals[i]) && energy(vals[i+1]))
{
j++;
}
}
for(unsigned i=0; (i < clusters.size()); i++)
{
for(unsigned j=0; (j < clusters[i].size()); j++)
{
cout << clusters[i][j] << ' ';
}
cout << endl;
}
}
输出是:
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
关于c++ - 将多个元素插入二维 block ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18876115/