public static string IntegerToCN(int value){string[] numberStrs = { "零", "一", "二", "三", "四", "五", "六", "七", "八", "九", "十" };if (value <= 10){value = Math.Max(0, value);return numberStrs[value];}string[] unitStrs = { "十", "百", "千", "", "十", "百", "千", "" };string unitWan = "万", unitYi = "亿";StringBuilder stringBuilder = new StringBuilder();int unitIndex = unitStrs.Length - 1;int unitInteger = 1_0000_0000;bool addZero = false;while (unitInteger > 0){int value1 = value / unitInteger;if (value1 > 0){if (addZero){stringBuilder.Append(numberStrs[0]);addZero = false;}stringBuilder.Append(numberStrs[value1]);if (unitIndex >= 0){stringBuilder.Append(unitStrs[unitIndex]);}var newValue = value - value1 * unitInteger;if (newValue < unitInteger / 10){addZero = true;}if (value >= 1_0000_0000 && newValue < 1_0000_0000){stringBuilder.Append(unitYi);}else if (value >= 1_0000 && newValue < 1_0000){stringBuilder.Append(unitWan);}value = newValue;}unitIndex--;unitInteger = unitInteger / 10;}return stringBuilder.ToString();}

            while (true){var inputStr = Console.ReadLine();Console.WriteLine(IntegerToCN(int.Parse(inputStr)));}

测试: 输入: 123456789
输出: 一亿二千三百四十五万六千七百八十九