再用n2的时间（两重循环）枚举d-c，并将b-c的值作为键，在Hash数组中查找是否存在。如果能找到critical相同的node点，则找到了一组满足 d-c = a+b的值。（注意检查a b c d 四个数不重复） Live vegetation are more than just decorative elements in a freshwater aquarium. They add to oxygenation, help maintain h2o high-quality, and supply normal habitats for fish. ● पोस्ट, स्टोरीज़, प्रीमियर्स, और लाइ... https://pearlaquatics.my/author/jasun/page/3/