1031. Hello World for U 解析

注意端点值，不然有的示例不能过。

#include <iostream>#include <string>using namespace std;int main() {	string s;	cin >> s;	int N = s.size();	int n1 = 1, n2 = 2;	int  maxn1 = -1, maxn2 = -1;	for (n2 = 3; n2 <= N; n2++) {		for (n1 = 1; n1 <= n2; n1++) {			if (n1 + n1 + n2 - 2 == N) {				if (n1 > maxn1) {					maxn1 = n1;					maxn2 = n2;				}			}		}	}	for (int i = 0; i < maxn1 -1; i++) {		cout << s[i];		for (int j = 0; j < maxn2 - 2; j++) {			cout << " ";		}		cout << s[N - i - 1] << endl;	}	for (int i = 0; i < maxn2; i++) {		cout << s[maxn1 - 1 + i];	}	cout << endl;//	cout << maxn1 << " " << maxn2 << endl;	system("pause");	return 0;	}