C++ does not have its own function for splitting strings,
so implement one yourself.
Split requirements:
Input:
1,24,569,78954,0,9,1,1111,230Output
these numbers
Implementation code:
#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
using namespace std;
vector<string> splitString(string str,char split){
//分割字符串 返回字符串数组
vector<string> res;
string s = "";
for (int i = 0; i < str.length();i++){
if(str[i]==split){
//遇到分隔符
res.push_back(s);
s = "";
}else if(i==str.length()-1){
//遇到结尾
s += str[i];
res.push_back(s);
s = "";
break;
}
else{
s += str[i];
}
}
return res;
}
int main(){
string str;
vector<int> res;
cin >> str;
vector<string> input = splitString(str,',');//确定分割符
for (int i = 0; i < input.size();i++)
{
//cout << input[i] << endl; //输出分割的字符串
int x = stoi(input[i]); //字符串转化为十进制数字 头文件string
cout << x << endl;//输出数字
}
return 0;
}
Input:
1,24,569,78954,0,9,1,1111,230
Output:
1
24
569
78954
0
9
1
1111
230
expand:
If you enter:
1:23,7:789,8:34,9:56,6:123,2:396,
this is a set of key-value pairs. Each pair is separated by a colon, and each pair is separated by a comma
. Output the results of sorting each pair of numbers, sorted by the first number in each pair from small to large.
Implementation code:
#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
using namespace std;
vector<string> splitString(string str,char split){
//分割字符串 返回字符串数组
vector<string> res;
string s = "";
for (int i = 0; i < str.length();i++){
if(str[i]==split){
//遇到分隔符
res.push_back(s);
s = "";
}else if(i==str.length()-1){
//遇到结尾
s += str[i];
res.push_back(s);
s = "";
break;
}
else{
s += str[i];
}
}
return res;
}
struct mypair{
int a;
int b;
};
int main(){
string str;
cin >> str;
vector<mypair> res;
vector<string> input = splitString(str,',');
for (int i = 0; i < input.size();i++)
{
vector<string> p = splitString(input[i], ':');
struct mypair x;
x.a = stoi(p[0]);
x.b = stoi(p[1]);
res.push_back(x);
}
auto cmp = [](struct mypair x, struct mypair y){
return x.a < y.a;
};
sort(res.begin(), res.end(), cmp);//排序
for (auto i : res){
cout << i.a << ":" << i.b << endl;
}
return 0;
}
Supplement:
If the input is as follows, it is required that only exchange operations can be performed. Find the minimum number of exchanges required to sort a sequence
2
A7 A2 A3 A4 A5 A6 A1 A2
A1 A3 A6 A5 A4 A7
#include <iostream>
#include <vector>
#include <map>
#include <string>
#include <algorithm>
using namespace std;
vector<string> splitString(string str,char split){
vector<string> res;
string s = "";
for (int i = 0; i < str.length();i++){
if(str[i]==split){
res.push_back(s);
s = "";
}else if(i==str.length()-1){
s += str[i];
res.push_back(s);
s = "";
break;
}
else{
s += str[i];
}
}
return res;
}
int getMinSwaps(vector<int> &nums){
map<int, int>mp;
vector<int> sortedNums(nums);
sort(sortedNums.begin(), sortedNums.end());
for (int i = 0; i < sortedNums.size(); i++)mp[sortedNums[i]] = i ;
int cnt = 0;
for (int i = 0; i < nums.size();i++)
{
if (nums[i] == sortedNums[i])continue;
swap(nums[i], nums[mp[nums[i]]]);
cnt++;
}
return cnt;
}
int main() {
int n;
cin >> n;
getchar();//吞掉后面的换行符
while(n--){
string str;
vector<int> a;
getline(cin, str);//有空格的时候 需要用getline读入
vector<string> res = splitString(str, ' ');
for (int i = 0; i < res.size();i++){
string temp = res[i];
string s = "";
for (int j = 1; j < temp.length();j++)
s += temp[j];
int x = stoi(s);
a.push_back(x);
}
cout << getMinSwaps(a) << endl;
}
return 0;
}