使用C++离散分布，权重取自数据结构

std::vector<int> values = {1, 2, 3, 4};
std::vector<double> weights = {0.1, 0.3, 0.4, 0.2};

double totalWeight = 0.0;
for (double weight : weights) {
    totalWeight += weight;
}

double randomValue = (double)rand() / RAND_MAX;  // 生成0到1之间的随机数
double cumulativeWeight = 0.0;
int selectedValue = 0;
for (int i = 0; i < values.size(); i++) {
    cumulativeWeight += weights[i] / totalWeight;
    if (randomValue <= cumulativeWeight) {
        selectedValue = values[i];
        break;
    }
}