【入门6】函数与结构体 - 题单 - 洛谷

P5461 赦免战俘

赦免战俘 - 洛谷

1:分治

#include<bits/stdc++.h>
using namespace std;
const int maxn = 1 << 11;
int N, M, MAP[maxn][maxn];
void Init(int len, int x, int y)
{
	if (len == 2)
	{
		MAP[x][y] = 0;
		return;
	}
	for (int i = x; i <= x + len / 2 - 1; i++)
		for (int j = y; j <= y + len / 2 - 1; j++)
			MAP[i][j] = 0;
	Init(len / 2, x + len / 2, y);
	Init(len / 2, x + len / 2, y + len / 2);
	Init(len / 2, x ,y + len / 2);
}
int main()
{
	cin >> N;
	M = 1 << N;
    fill(MAP[0], MAP[0] + sizeof(MAP) / sizeof(int), 1);
	Init(M, 1, 1);
	for (int i = 1; i <= M; i++)
	{
		for (int j = 1; j <= M; j++)
			cout << MAP[i][j] << " ";
		cout << endl;
	}
	return 0;
}

2:杨辉递推

3:位运算

P2415 集合求和

集合求和 - 洛谷

找规律,n个数,对于每一个数出现 n - 1次

#include<bits/stdc++.h>
using namespace std;
long long  num, sum, n;
int  main()
{
    while (cin >> num)sum += num, n++;
    while (--n)sum *= 2;
    printf("%lld",sum);
    return 0;
}