C++ ＜map＞ ＜key, value＞

map

测试代码键值排序

测试代码

#include <string> #include <iostream> #include <map> #include <stdlib.h> using namespace std; int main(void) { map<int, string> mapStu; mapStu.insert(pair<int, string>(1, "张三")); mapStu.insert(pair<int, string>(2, "李四")); mapStu.insert(pair<int, string>(3, "王五")); mapStu.insert(pair<int, string>(4, "赵六")); mapStu[5] = mapStu[6]; mapStu[7] = mapStu[4]; /*pair<map<int, string>::iterator, bool> ret = mapStu.insert(pair<int, string>(1, "小张三")); if (ret.second == true) { cout << "键值插入成功：" << ret.second << endl; } else { cout << "插入失败！" << endl; } mapStu.insert(make_pair(2, "李四")); mapStu.insert(map<int, string>::value_type(3, "王五")); mapStu[4] = "张飞";*/ for (map<int, string>::iterator it = mapStu.begin(); it != mapStu.end(); ++it) { cout << "key: " << (*it).first << " value: " << (*it).second << endl; } system("pause"); return 0; }

键值排序

#include <string> #include <iostream> #include <map> #include <stdlib.h> using namespace std; int main(void) { //从大到小排序greater<int> map<int, string, greater<int>> mapStu;//默认排序方式 less<int> mapStu.insert(make_pair(1, "张三")); mapStu.insert(make_pair(2, "李四")); mapStu.insert(make_pair(3, "王五")); mapStu.insert(make_pair(4, "赵六")); for (map<int, string, greater<int>>::iterator it = mapStu.begin(); it != mapStu.end(); ++it) { cout << "key: " << (*it).first << " value: " << (*it).second << endl; } system("pause"); return 0; }