我坚持使用我对 Project Euler 问题 4 的解决方案，我有以下代码应该可以工作，并且它确实遍历了我研究和发现的问题的解决方案（993 * 913）：
// Michael Clover
// Project Euler
// Problem 4
/* A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 99.
Find the largest palindrome made from the product of two 3-digit numbers. */
#include <iostream>
#include <string>
#include <sstream>
#include <cstdlib>
using namespace std;
bool achieved = false; // change to true when the palindrome is found
string string_conversion = "";
string first_half = ""; // first half of string
string second_half = ""; // second half of string
stringstream conversion; // use this to convert integers to strings
int check(string first_half, string second_half) {
if (first_half.compare(second_half) == 0) {
achieved = true;
return 0;
}
else {
return 0;
}
return 0;
}
int convert(int result) {
char temp;
conversion << result;
conversion >> string_conversion;
if (string_conversion.size() == 6) {
temp = string_conversion.at(0);
//cout << "temp = " << temp << endl;
first_half+=(temp);
temp = string_conversion.at(1);
//cout << "temp = " << temp << endl;
first_half+=(temp);
temp = string_conversion.at(2);
//cout << "temp = " << temp << endl;
first_half+=(temp);
temp = string_conversion.at(5);
//cout << "temp = " << temp << endl;
second_half+=(temp);
temp = string_conversion.at(4);
//cout << "temp = " << temp << endl;
second_half+=(temp);
temp = string_conversion.at(3);
//cout << "temp = " << temp << endl;
second_half+=(temp);
//cout << first_half << second_half << endl;
check(first_half, second_half);
}
//if (string_conversion.size() == 5) {
//cout << "The size of the string is 5" << endl;
//exit(1);
//}
string_conversion = "";
cout << first_half << endl;
cout << second_half << endl;
first_half.clear();
second_half.clear();
conversion.clear();
conversion.str("");
//cout << "conversion: " << conversion << endl;
return 0;
}
int iterate(int operator_one, int operator_two) { // takes two numbers and iterates through them, each time it is iterated, the result is passed to the convert function to convert to string
int two = operator_two;
for (int i = operator_one; i > 100; i--) {
int result = i * two;
cout << i << "x" << two << endl;
convert(result);
}
return 0;
}
int main() { // Use the stringstream to convert the numerical values into strings which you can then use to check if they are palindromes
int operator_one = 999;
int operator_two = 999;
while (achieved == false) {
for (int i = operator_two; i > 100; i--) {
iterate(999, i);
}
}
cout << "The largest palindrome made from the product of two 3-digit numbers is: " << string_conversion << endl;
return 0;
}
该程序向下遍历 999x999 的所有数字，然后将 6 位数字拆分为两个字符串，结果的后半部分从后向前排列。如控制台在运行时使用 cout << 所示，程序尝试 993*913 并且 second_half 字符串和 first_half 字符串都包含 906。我认为程序应该做的是执行 check(string first_half, string second_half) 函数在迭代此并确定两个字符串匹配（应根据各种来源返回 0）之后，这应该在 check() 中启动 if 语句并将实现的布尔值设置为 true 在主语句中结束程序并打印结果在退出程序之前。然而它并没有这样做，这是我的问题。感谢您的任何帮助。