Statistics.h

/*-----------------------------------------------------------------------
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regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"; you may not use this file except in compliance
with the License.  You may obtain a copy of the License at
 
  http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
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-----------------------------------------------------------------------*/
#pragma once
 
#include <cstddef>
#include <utility>
#include <stdexcept>
 
namespace statistics
{
    template <class T>
    std::pair<T, T> getMinMax(
        const T* values,
        const T & noValue,
        const size_t & valueCount)
    {
        if (valueCount == 0) {
            throw std::invalid_argument("You cannot compute min max on an empty array.");
        }
 
        std::pair<T, T> minMax(noValue, noValue);
        size_t i = 0;
        while (i < valueCount && (values[i] != values[i] || values[i] == noValue)) ++i;
        if (i < valueCount)
        {
            minMax.first = values[i];
            minMax.second = values[i];
        }
        for (; i < valueCount; ++i)
        {
            if (values[i] == values[i] && values[i] != noValue)
            {
                if (values[i] > minMax.second)
                    minMax.second = values[i];
                else if (values[i] < minMax.first)
                    minMax.first = values[i];
            }
        }
 
        return minMax;
    }
    
}