如何按值对STL映射排序? [英] How can I sort an STL map by value?

问题描述

如何实现按值对STL映射进行排序?

How can I implement STL map sorting by value?

例如，我有一张地图m:

map<int, int> m;
m[1] = 10;
m[2] = 5;
m[4] = 6;
m[6] = 1;

我想按m的值对该地图进行排序.因此，如果我打印地图，则希望得到如下结果:

I'd like to sort that map by m's value. So, if I print the map, I'd like to get the result as follows:

m[6] = 1
m[2] = 5
m[4] = 6
m[1] = 10

如何以这种方式对地图进行排序?有什么方法可以处理具有排序值的键和值?

How can I sort the map in this way? Is there any way that I can deal with the key and value with sorted values?

推荐答案

您可以构建第二张地图，第一张地图的值作为键，第一张地图的键作为值.

You can build a second map, with the first map's values as keys and the first map's keys as values.

这仅在所有值都不同时才起作用.如果您不能假设这一点，则需要构建一个多图而不是一个图.

This works only if all values are distinct. If you cannot assume this, then you need to build a multimap instead of a map.

这篇关于如何按值对STL映射排序?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！