P1067 [NOIP2009 普及组] 多项式输出

 

 解题思路：

把各种情况写上就好

#include<iostream>
using namespace std;
int n, ans[105];

int main()
{
	cin >> n;
	int i, o;
	for (i = 0; i <= n; ++i) cin >> ans[i];
	if (ans[0] != 0) {
		if (ans[0] == 1) cout << "x^" << n;
		else if (ans[0] == -1) cout << "-x^" << n;
		else cout << ans[0] << "x^" << n;
	}
	--n;
	for (i = 1; n>=0; ++i) {
		if (ans[i] != 0) {
			if (n == 1) {
				if (ans[i] == 1) cout << "+x";
				else if (ans[i] == -1) cout << "-x";
				else if (ans[i] != 1 && ans[i] > 0) cout << "+" << ans[i] << "x";
				else cout << ans[i] << "x";
			}
			else if (n == 0) {
				if (ans[i] > 0) cout << "+" << ans[i];
				else cout << ans[i];
			}
			else if (ans[i] == 1) cout << "+x^" << n;
			else if (ans[i] == -1) cout << "-x^" << n;
			else if (ans[i] != 1 && ans[i] > 0) cout << "+" << ans[i] << "x^" << n;
			else cout << ans[i] << "x^" << n;
			--n;
		}
		else --n;
	}
	return 0;
}