【C++】正向&逆向遍历map

最后更新日期：
2023.10.11

1.正向遍历map

map<int, int> test_map;
for(auto it = test_map.begin(); it != test_map.end(); it++){
	cout << it->first << " " << it->second << endl;
}

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2.逆向遍历map

map<int, int> test_map;
for(auto it = test_map.rbegin(); it != test_map.rend(); it++){
	cout << it->first << " " << it->second << endl;
}
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3.举例

#include 
#include
#include
using namespace std;

int main() {
	map<int, int> test_map;
	vector<int> vec = {11, 32, 33, 45, 51, 36, 27, 84, 29};
	
	for(int i = 0; i < vec.size(); i++){
		test_map[i] = vec[i];
	}
	
	for(auto it = test_map.begin(); it != test_map.end(); it++)
		cout << it->first << " " << it->second << endl;
		
	cout << endl;
		
	for(auto it = test_map.rbegin(); it != test_map.rend(); it++)
		cout << it->first << " " << it->second << endl;
		
	return 0;
}
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运行结果：

0 11
1 32
2 33
3 45
4 51
5 36
6 27
7 84
8 29

8 29
7 84
6 27
5 36
4 51
3 45
2 33
1 32
0 11
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以上。