C和C++常用代码片段整理
整理一些C和C++常用的代码片段，方便自己快速开发。先总结一些C++的，C++支持函数重载，写得爽些。
main.cpp：
#include <iostream>
#include <set>
#include <map>
#include "util.h"
using namespace std;
int main() {
cout << "sandeepin poi!" << endl;
// 时间戳
cout << "Timestamp:" << "\n";
cout << "us(ll):" << currentTimeUs() << "\n";
cout << "us(str):" << currentTimeUsStr() << "\n";
cout << "ms(ll):" << currentTimeMs() << "\n";
cout << "ms(str)::" << currentTimeMsStr() << "\n\n";
// 读写文件
cout << "File IO:" << "\n";
save("test.txt", "jfz poi");
saveAppend("test.txt", "jfz sandeepin");
vector<string> txtVec = read("test.txt");
// 展示数据
show("read result:");
show(txtVec);
// 类型转换
// string操作
// Set封装
show("TreeSet:");
// set<string> treeSet;
unordered_set<string> treeSet;
// 增
treeSet.insert("jfz");
treeSet.insert("poi");
treeSet.insert("sandeepin");
treeSet.insert("Sandeepin");
// 删
treeSet.erase("sandeepin");
// 查(包含)
if (treeSet.find("poi") != treeSet.end()) {
show("contains:poi");
}
// 查(遍历)
for (const auto &item : treeSet) {
show(item);
}
// 清空
treeSet.clear();
show(to_string(treeSet.size()));
// 封装
vector<string> vct = {"789", "123", "456"};
setAddAll(treeSet, vct);
show(treeSet);
setAdd(treeSet, "000");
setRemove(treeSet, "456");
show(to_string(setContains(treeSet, "456")));
show(to_string(setContains(treeSet, "000")));
show(treeSet);
setRemoveAll(treeSet);
show(treeSet);
// Map封装
show("TreeMap:");
map<string, string> treeMap;
// unordered_map<string, string> treeMap;
// 增
treeMap.insert(pair<string, string>("jfz", "poi"));
treeMap["123"] = "456";
treeMap["abc"] = "hahaha";
// 删
treeMap.erase("123");
// 查(包含)
if (treeMap.find("abc") != treeMap.end()) {
show("contains:abc");
}
// 查(遍历)
for (const auto &item : treeMap) {
show(item.first + " " + item.second);
}
// 清空
treeMap.clear();
show(to_string(treeMap.size()));
// 封装
treeMap["123"] = "456";
treeMap["kxy"] = "opq";
treeMap["_we3"] = "Sandeepin";
show(treeMap);
mapPut(treeMap, "000", "999");
show(mapGet(treeMap, "000"));
mapPut(treeMap, "000", "888");
show(mapGet(treeMap, "000"));
mapRemove(treeMap, "123");
show(to_string(mapContainsKey(treeMap, "kxy")));
show(to_string(mapContainsKey(treeMap, "ffff")));
show(to_string(mapContainsValue(treeMap, "Sandeepin")));
show(to_string(mapContainsValue(treeMap, "zaqwsxcde")));
show(treeMap);
mapRemoveAll(treeMap);
show(treeMap);
return 0;
}
util.h：
#ifndef JFZLIBRARY_UTIL_H
#define JFZLIBRARY_UTIL_H
#include <string>
#include <vector>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
long long currentTimeUs();
long long currentTimeMs();
std::string currentTimeUsStr();
std::string currentTimeMsStr();
void save(const std::string &fileName, const std::string &str);
void saveAppend(const std::string &fileName, const std::string &str);
std::vector<std::string> read(const std::string &fileName);
void show(const std::string &text);
void show(const std::vector<std::string> &vct);
void show(std::set<std::string> &set);
void show(std::unordered_set<std::string> &set);
void show(std::map<std::string, std::string> &map);
void show(std::unordered_map<std::string, std::string> &map);
/* TreeSet */
void setAdd(std::set<std::string> &set, const std::string &item);
void setRemove(std::set<std::string> &set, const std::string &item);
bool setContains(std::set<std::string> &set, const std::string &item);
void setAddAll(std::set<std::string> &set, const std::vector<std::string> &vct);
void setRemoveAll(std::set<std::string> &set);
/* HashSet */
void setAdd(std::unordered_set<std::string> &set, const std::string &item);
void setRemove(std::unordered_set<std::string> &set, const std::string &item);
bool setContains(std::unordered_set<std::string> &set, const std::string &item);
void setAddAll(std::unordered_set<std::string> &set, const std::vector<std::string> &vct);
void setRemoveAll(std::unordered_set<std::string> &set);
/* TreeMap */
void mapPut(std::map<std::string, std::string> &map, const std::string &key, const std::string &value);
std::string mapGet(std::map<std::string, std::string> &map, const std::string &key);
void mapRemove(std::map<std::string, std::string> &map, const std::string &key);
bool mapContainsKey(std::map<std::string, std::string> &map, const std::string &key);
bool mapContainsValue(std::map<std::string, std::string> &map, const std::string &value);
void mapRemoveAll(std::map<std::string, std::string> &map);
/* HashMap */
void mapPut(std::unordered_map<std::string, std::string> &map, const std::string &key, const std::string &value);
std::string mapGet(std::unordered_map<std::string, std::string> &map, const std::string &key);
void mapRemove(std::unordered_map<std::string, std::string> &map, const std::string &key);
bool mapContainsKey(std::unordered_map<std::string, std::string> &map, const std::string &key);
bool mapContainsValue(std::unordered_map<std::string, std::string> &map, const std::string &value);
void mapRemoveAll(std::unordered_map<std::string, std::string> &map);
#endif //JFZLIBRARY_UTIL_H
util.cpp：
#include <sys/time.h>
#include <string>
#include <fstream>
#include <vector>
#include <iostream>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
long long currentTimeUs() {
struct timeval currentTimeMillis{};
gettimeofday(¤tTimeMillis, nullptr);
long long sec = currentTimeMillis.tv_sec;
long long usec = currentTimeMillis.tv_usec;
long long time = sec * 1000000 + usec;
return time;
}
long long currentTimeMs() {
return currentTimeUs() / 1000;
}
std::string currentTimeUsStr() {
return std::to_string(currentTimeUs());
}
std::string currentTimeMsStr() {
return std::to_string(currentTimeMs());
}
void save(const std::string &fileName, const std::string &str) {
if (fileName.empty()) {
return;
}
std::ofstream file;
if (file.bad()) {
return;
}
file.open(fileName, std::ios::ate);
file << str << "\n";
file.close();
}
void saveAppend(const std::string &fileName, const std::string &str) {
if (fileName.empty()) {
return;
}
std::ofstream file;
if (file.bad()) {
return;
}
file.open(fileName, std::ios::app);
file << str << "\n";
file.close();
}
std::vector<std::string> read(const std::string &fileName) {
std::vector<std::string> out;
if (fileName.empty()) {
return out;
}
std::ifstream inFile;
inFile.open(fileName, std::ios::in);
if (inFile.bad()) {
return out;
}
std::string str;
while (getline(inFile, str)) {
out.push_back(str);
}
return out;
}
void show(const std::string &text) {
std::cout << text << "\n";
}
void show(const std::vector<std::string> &vct) {
for (const auto &i : vct) {
std::cout << i << "\n";
}
}
void show(std::set<std::string> &set) {
for (const auto &i : set) {
std::cout << i << "\n";
}
}
void show(std::unordered_set<std::string> &set) {
for (const auto &i : set) {
std::cout << i << "\n";
}
}
void show(std::map<std::string, std::string> &map) {
for (const auto &i : map) {
std::cout << i.first << " " << i.second << "\n";
}
}
void show(std::unordered_map<std::string, std::string> &map) {
for (const auto &i : map) {
std::cout << i.first << " " << i.second << "\n";
}
}
/* TreeSet */
void setAdd(std::set<std::string> &set, const std::string &item) {
set.insert(item);
}
void setRemove(std::set<std::string> &set, const std::string &item) {
set.erase(item);
}
bool setContains(std::set<std::string> &set, const std::string &item) {
return set.find(item) != set.end();
}
void setAddAll(std::set<std::string> &set, const std::vector<std::string> &vct) {
for (const auto &item : vct) {
set.insert(item);
}
}
void setRemoveAll(std::set<std::string> &set) {
set.clear();
}
/* HashSet */
void setAdd(std::unordered_set<std::string> &set, const std::string &item) {
set.insert(item);
}
void setRemove(std::unordered_set<std::string> &set, const std::string &item) {
set.erase(item);
}
bool setContains(std::unordered_set<std::string> &set, const std::string &item) {
return set.find(item) != set.end();
}
void setAddAll(std::unordered_set<std::string> &set, const std::vector<std::string> &vct) {
for (const auto &item : vct) {
set.insert(item);
}
}
void setRemoveAll(std::unordered_set<std::string> &set) {
set.clear();
}
/* TreeMap */
void mapPut(std::map<std::string, std::string> &map, const std::string &key, const std::string &value) {
map[key] = value;
}
std::string mapGet(std::map<std::string, std::string> &map, const std::string &key) {
if (map.find(key) != map.end()) {
return map[key];
}
return "null";
}
void mapRemove(std::map<std::string, std::string> &map, const std::string &key) {
map.erase(key);
}
bool mapContainsKey(std::map<std::string, std::string> &map, const std::string &key) {
return map.find(key) != map.end();
}
bool mapContainsValue(std::map<std::string, std::string> &map, const std::string &value) {
for (const auto &i : map) {
if (i.second == value) {
return true;
}
}
return false;
}
void mapRemoveAll(std::map<std::string, std::string> &map) {
map.clear();
}
/* HashMap */
void mapPut(std::unordered_map<std::string, std::string> &map, const std::string &key, const std::string &value) {
map[key] = value;
}
std::string mapGet(std::unordered_map<std::string, std::string> &map, const std::string &key) {
if (map.find(key) != map.end()) {
return map[key];
}
return "null";
}
void mapRemove(std::unordered_map<std::string, std::string> &map, const std::string &key) {
map.erase(key);
}
bool mapContainsKey(std::unordered_map<std::string, std::string> &map, const std::string &key) {
return map.find(key) != map.end();
}
bool mapContainsValue(std::unordered_map<std::string, std::string> &map, const std::string &value) {
for (const auto &i : map) {
if (i.second == value) {
return true;
}
}
return false;
}
void mapRemoveAll(std::unordered_map<std::string, std::string> &map) {
map.clear();
}
接下来总结一些C语音的，主要是在底层编码的时候用上：