好的！下面是对每道题目的C++代码实现，帮助你练习和理解字符串的操作。
1. 字符串长度
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| #include <iostream>
#include <string>
using namespace std;
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
cout << "字符串长度为: " << str.length() << endl;
return 0;
}
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2. 字符串反转
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| #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
reverse(str.begin(), str.end());
cout << "反转后的字符串: " << str << endl;
return 0;
}
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3. 字符串比较
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| #include <iostream>
#include <string>
using namespace std;
bool compareStrings(string str1, string str2) {
if (str1.length() != str2.length()) return false;
for (int i = 0; i < str1.length(); i++) {
if (str1[i] != str2[i]) return false;
}
return true;
}
int main() {
string str1, str2;
cout << "请输入第一个字符串: ";
getline(cin, str1);
cout << "请输入第二个字符串: ";
getline(cin, str2);
if (compareStrings(str1, str2))
cout << "两个字符串相等" << endl;
else
cout << "两个字符串不相等" << endl;
return 0;
}
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4. 统计字符串中的字符个数
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| #include <iostream>
#include <map>
#include <string>
using namespace std;
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
map<char, int> charCount;
for (char ch : str) {
charCount[ch]++;
}
for (auto &pair : charCount) {
cout << pair.first << ": " << pair.second << endl;
}
return 0;
}
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5. 大写字母转小写
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| #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
transform(str.begin(), str.end(), str.begin(), ::tolower);
cout << "转换后的字符串: " << str << endl;
return 0;
}
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6. 查找子串
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| #include <iostream>
#include <string>
using namespace std;
int main() {
string str, substr;
cout << "请输入主字符串: ";
getline(cin, str);
cout << "请输入子字符串: ";
getline(cin, substr);
int pos = str.find(substr);
if (pos != string::npos) {
cout << "子串起始位置: " << pos << endl;
} else {
cout << "子串未找到" << endl;
}
return 0;
}
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7. 字符串旋转
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| #include <iostream>
#include <string>
using namespace std;
string rotateString(string str, int steps) {
int n = str.length();
steps = steps % n;
return str.substr(n - steps) + str.substr(0, n - steps);
}
int main() {
string str;
int steps;
cout << "请输入字符串: ";
getline(cin, str);
cout << "请输入右移步数: ";
cin >> steps;
cout << "旋转后的字符串: " << rotateString(str, steps) << endl;
return 0;
}
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8. 统计单词数量
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| #include <iostream>
#include <string>
#include <sstream>
using namespace std;
int main() {
string str;
cout << "请输入一句话: ";
getline(cin, str);
stringstream ss(str);
string word;
int count = 0;
while (ss >> word) {
count++;
}
cout << "单词数量: " << count << endl;
return 0;
}
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9. 删除特定字符
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| #include <iostream>
#include <string>
using namespace std;
int main() {
string str;
char ch;
cout << "请输入字符串: ";
getline(cin, str);
cout << "请输入要删除的字符: ";
cin >> ch;
str.erase(remove(str.begin(), str.end(), ch), str.end());
cout << "删除后的字符串: " << str << endl;
return 0;
}
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10. 回文判断
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| #include <iostream>
#include <string>
using namespace std;
bool isPalindrome(string str) {
int i = 0, j = str.length() - 1;
while (i < j) {
if (str[i] != str[j]) return false;
i++;
j--;
}
return true;
}
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
if (isPalindrome(str)) {
cout << "是回文字符串" << endl;
} else {
cout << "不是回文字符串" << endl;
}
return 0;
}
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11. 最长公共前缀
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| #include <iostream>
#include <vector>
#include <string>
using namespace std;
string longestCommonPrefix(vector<string>& strs) {
if (strs.empty()) return "";
string prefix = strs[0];
for (int i = 1; i < strs.size(); i++) {
while (strs[i].find(prefix) != 0) {
prefix = prefix.substr(0, prefix.length() - 1);
if (prefix.empty()) return "";
}
}
return prefix;
}
int main() {
vector<string> strs = {"flower", "flow", "flight"};
cout << "最长公共前缀为: " << longestCommonPrefix(strs) << endl;
return 0;
}
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12. 字符串压缩
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| #include <iostream>
#include <string>
using namespace std;
string compressString(string str) {
string result = "";
int count = 1;
for (int i = 1; i <= str.length(); i++) {
if (i < str.length() && str[i] == str[i-1]) {
count++;
} else {
result += str[i-1];
result += to_string(count);
count = 1;
}
}
return result.length() < str.length() ? result : str;
}
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
cout << "压缩后的字符串: " << compressString(str) << endl;
return 0;
}
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13. 最长不重复子串
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| #include <iostream>
#include <string>
#include <unordered_map>
using namespace std;
int lengthOfLongestSubstring(string str) {
unordered_map<char, int> charIndex;
int maxLength = 0, start = 0;
for (int i = 0; i < str.length(); i++) {
if (charIndex.find(str[i]) != charIndex.end() && charIndex[str[i]] >= start) {
start = charIndex[str[i]] + 1;
}
charIndex[str[i]] = i;
maxLength = max(maxLength, i - start + 1);
}
return maxLength;
}
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
cout << "最长不重复子串的长度: " << lengthOfLongestSubstring(str) << endl;
return 0;
}
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14. 字符串排列
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| #include <iostream>
#include <string>
#include <algorithm>
using namespace std;
void permute(string str, int l, int r) {
if (l == r)
cout << str << endl;
else {
for (int i = l; i <= r; i++) {
swap(str[l], str[i]);
permute(str, l + 1, r);
swap(str[l], str[i]);
}
}
}
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
permute(str, 0, str.length() - 1);
return 0;
}
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15. 字符串中的第一个唯一字符
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| #include <iostream>
#include <unordered_map>
#include <string>
using namespace std;
int firstUniqueChar(string str) {
unordered_map<char, int> charCount;
for (char ch : str) {
charCount[ch]++;
}
for (int i = 0; i < str.length(); i++) {
if (charCount[str[i]] == 1) {
return i;
}
}
return -1;
}
int main() {
string str;
cout << "请输入字符串: ";
getline(cin, str);
int index = firstUniqueChar(str);
if (index != -1)
cout << "第一个唯一字符的索引是: " << index
<< endl;
else
cout << "没有唯一字符" << endl;
return 0;
}
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