sortstring
时间: 2023-11-21 20:05:28 浏览: 74
以下是两种对字符串进行排序的例子:
1. 对单个字符串进行排序
```cpp
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
string s;
cin >> s;
sort(s.begin(), s.end());
cout << s << endl;
return 0;
}
```
2. 对字符串数组进行排序
```cpp
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
string ss[5];
int i = 0;
while(cin >> ss[i++]){
if(i == 5) break;
}
sort(ss, ss+5);
for(int j = 0; j < 5; j++){
cout << ss[j] << endl;
}
return 0;
}
```
相关问题
c++sort string
C++中的sort函数可以用来对给定区间的元素进行排序。在C++中,使用sort函数对字符串数组进行排序的方法如下所示:
1. 引入头文件和命名空间:
```cpp
#include <algorithm>
#include <string>
#include <vector>
using namespace std;
```
2. 编写排序函数:
```cpp
void sort_string(string* in_array, int n, string* out_array) {
vector<string> strArray;
for (int i = 0; i < n; i++) {
strArray.push_back(in_array[i]);
}
sort(strArray.begin(), strArray.end());
vector<string>::iterator st;
int j = 0;
for (st = strArray.begin(); st != strArray.end(); st++) {
out_array[j] = *st;
j++;
}
}
```
3. 调用排序函数并输出结果:
```cpp
int main() {
string str[4] = { "hello, world!", "welcome to cpp.", "effective c++", "exceptional c++" };
string str_out[4];
sort_string(str, 4, str_out);
for (int j = 0; j < 4; j++) {
cout << str_out[j] << endl;
}
}
```
以上代码中,首先将字符串数组转换为vector容器,然后使用sort函数对容器进行排序,最后将排序后的结果存入输出数组中并输出。
将下面代码优化一下, 只要一个函数 最终输出新的json字符串指针#include <stdio.h> #include <stdlib.h> #include <string.h> #include <openssl/hmac.h> #include "cJSON.h" char *sortJsonString(cJSON *json); char *getSign(char *jsonString, char *key); char *addSignToJson(char *jsonString, char *key, char *signKey); char *sortJsonString(cJSON *json) { int count = cJSON_GetArraySize(json); char **keys = (char **) malloc(count * sizeof(char *)); int i = 0; cJSON_ArrayForEach(json, json) { keys[i++] = strdup(json->string); } qsort(keys, count, sizeof(char *), strcmp); char *sortString = (char *) malloc(1); sortString[0] = '\0'; for (int i = 0; i < count; i++) { cJSON *item = cJSON_GetObjectItemCaseSensitive(json, keys[i]); if (item->type == cJSON_Object) { char *subSortString = sortJsonString(item); sortString = (char *) realloc(sortString, strlen(sortString) + strlen(keys[i]) + strlen(subSortString) + 3); sprintf(sortString + strlen(sortString), "%s=%s&", keys[i], subSortString); free(subSortString); } else { sortString = (char *) realloc(sortString, strlen(sortString) + strlen(keys[i]) + strlen(item->valuestring) + 3); sprintf(sortString + strlen(sortString), "%s=%s&", keys[i], item->valuestring); } } sortString[strlen(sortString) - 1] = '\0'; cJSON_ArrayForEach(json, json) { free(keys[--i]); } free(keys); return sortString; } char *getSign(char *jsonString, char *key) { char *sortString = sortJsonString(cJSON_Parse(jsonString)); unsigned char *hmac = HMAC(EVP_sha256(), key, strlen(key), (const unsigned char *) sortString, strlen(sortString), NULL, NULL); char *sign = (char *) malloc(65); for (int i = 0; i < 32; i++) { sprintf(&sign[i * 2], "%02x", hmac[i]); } sign[64] = '\0'; free(sortString); return sign; } char *addSignToJson(char *jsonString, char *key, char *signKey) { char *sign = getSign(jsonString, key); cJSON *json = cJSON_Parse(jsonString); cJSON_AddStringToObject(json, signKey, sign); char *result = cJSON_Print(json); free(sign); cJSON_Delete(json); return result; }
下面是对代码进行优化的结果,整合成了一个函数,并且使用了更加简洁的写法:
```
char *addSignToJson(char *jsonString, char *key, char *signKey) {
cJSON *json = cJSON_Parse(jsonString);
char *sortString = sortJsonString(json);
char *sign = getSign(sortString, key);
cJSON_AddStringToObject(json, signKey, sign);
char *result = cJSON_Print(json);
free(sortString);
free(sign);
cJSON_Delete(json);
return result;
}
```
这个函数将原来的三个函数整合成了一个,使用了更加简洁的写法,同时也减少了一些内存分配和释放的操作,提高了代码的效率和可读性。