PHP로 시뮬레이션 어닐링 알고리즘을 구현하는 방법

<?php
function simulatedAnnealing($initState, $initTemp, $finalTemp, $coolRate) {
    $currentTemp = $initTemp;
    $currentState = $initState;
    $bestState = $initState;
    $currentEnergy = calculateEnergy($currentState);
    $bestEnergy = $currentEnergy;

    while ($currentTemp > $finalTemp) {
        $newState = generateNeighbor($currentState);
        $newEnergy = calculateEnergy($newState);
        $energyDifference = $newEnergy - $currentEnergy;

        if ($energyDifference < 0) {
            $currentState = $newState;
            $currentEnergy = $newEnergy;
            if ($newEnergy < $bestEnergy) {
                $bestState = $newState;
                $bestEnergy = $newEnergy;
            }
        } else {
            $random = mt_rand() / mt_getrandmax();
            $acceptProbability = exp(-$energyDifference / $currentTemp);
            if ($random < $acceptProbability) {
                $currentState = $newState;
                $currentEnergy = $newEnergy;
            }
        }

        $currentTemp *= $coolRate;
    }

    return $bestState;
}

function calculateEnergy($state) {
    // 计算函数值，根据具体问题进行定义
    // 这里以一个简单的函数为例
    $x = $state;
    $energy = pow($x, 2) - 10 * cos(2 * M_PI * $x);

    return $energy;
}

function generateNeighbor($state) {
    // 生成邻域解，根据具体问题进行定义
    // 这里以一个简单的生成随机数的方式为例
    $neighbor = $state + (mt_rand() / mt_getrandmax()) * 2 - 1;

    return $neighbor;
}

// 示例调用
$initState = 0;
$initTemp = 100;
$finalTemp = 0.1;
$coolRate = 0.9;

$bestState = simulatedAnnealing($initState, $initTemp, $finalTemp, $coolRate);
echo "Best state: " . $bestState . "
";
echo "Best energy: " . calculateEnergy($bestState) . "
";
?>