本帖最后由 Highway 于 2015-3-25 00:03 编辑
第四题:
最小四位数:1204
最大四位数:1758
全部可能的四位数组合:128
[1204, 1206, 1208, 1234, 1235, 1236, 1238, 1239, 1240, 1243, 1245, 1247, 1248, 1253, 1254, 1256, 1257, 1258, 1270, 1273, 1274, 1275, 1279, 1280, 1283, 1284, 1285, 1289, 1293, 1297, 1298, 1324, 1326, 1328, 1340, 1342, 1346, 1347, 1349, 1362, 1367, 1369, 1370, 1372, 1374, 1376, 1378, 1380, 1382, 1386, 1387, 1389, 1394, 1396, 1398, 1403, 1407, 1408, 1423, 1427, 1428, 1463, 1467, 1468, 1503, 1507, 1508, 1523, 1524, 1526, 1527, 1528, 1540, 1542, 1546, 1547, 1549, 1562, 1563, 1567, 1568, 1569, 1570, 1572, 1574, 1576, 1578, 1580, 1582, 1586, 1587, 1589, 1594, 1596, 1598, 1634, 1635, 1639, 1640, 1643, 1645, 1647, 1648, 1653, 1657, 1658, 1670, 1673, 1674, 1675, 1679, 1680, 1683, 1684, 1685, 1689, 1693, 1697, 1698, 1704, 1706, 1708, 1734, 1736, 1738, 1754, 1756, 1758]
如果愿意动脑筋的话,可以把1998改成2015,那么答案会是什么样呢? |