P1216[USACO1.5] [IOI1994]数字三角形 Number Triangles

#include
using namespace std;
int num[1001][1001];
int main() {
	int r;
	cin >> r;
	for (int i = 1; i <= r; i++) {
		for (int j = 1; j <= i; j++) {
			cin >> num[i][j];
		}
	}
	for (int i = r - 1; i >= 1; i--) {
		for (int j = 1; j <= i; j++) {
			num[i][j] = max(num[i + 1][j] + num[i][j], num[i + 1][j + 1] + num[i][j]);
		}
	}
	cout << num[1][1];
	return 0;
}