PTA刷题记录：L1-023 输出GPLT (20分)

#include <iostream>
#include <string>

using namespace std;

int main() {
	int nG = 0;
	int nP = 0;
	int nL = 0;
	int nT = 0;
	string str;
	
	cin >> str;
	
	for (string::iterator i = str.begin(); i != str.end(); i++) {
		if (*i == 'G' || *i == 'g') {
			nG++;
		} else if (*i == 'P' || *i == 'p') {
			nP++;
		} else if (*i == 'L' || *i == 'l') {
			nL++;
		} else if (*i == 'T' || *i == 't') {
			nT++;
		} else {
			continue;
		}
	}
	for (;nG != 0 || nP != 0 || nL != 0 || nT != 0;) {
		if (nG != 0) {
			cout << 'G'; nG--;
		} 
		if (nP != 0) {
			cout << 'P'; nP--;
		}
		if (nL != 0) {
			cout << 'L'; nL--;
		}
		if (nT != 0) {
			cout << 'T'; nT--;
		}
	}
	
	return 0;
}