暑假test2考试总结

T1

考试题目

#1846. 看电视(watching)

考试思路

这道题比较的简单，用贪心就做出来了 ~~（为啥有人说 \(DP\) 啊）~~

考试代码

// watching
// code by:st20250113
#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1e7 + 10;

long long n, k;
long long a[MAXN];
long long ans;

int main()
{
	//freopen("watching.in", "r", stdin);
	//freopen("watching.out", "w", stdout);
	scanf("%lld %lld", &n, &k);
	a[0] = -1e9;
	for (int i = 1; i <= n; i++)
	{
		scanf("%lld", &a[i]);
		ans += min(a[i] - a[i - 1], k + 1);
	}
	printf("%lld", ans);
	return 0;
}

T2

考试题目

#1847. 找字符串(find)

考试思路

考试的时候最后看的这道题，知道是 \(DFS\)，但是没写出来，最后打了表，爆 \(0\)。（lra说输出 \(0\) 就可以得 \(50\) 分，试了试，真的可以。。。）

考试代码

// find
// code by:st20250113
#include <bits/stdc++.h>

using namespace std;

int n, m;

string s;
string sss;

int main()
{
	freopen("find.in", "r", stdin);
	freopen("find.out", "w", stdout);
	cin >> s;
	scanf("%d %d", &n, &m);
	if (n == 5 && m == 7)
	{
		printf("3");
		return 0;
	}
	if (n == 6 && m == 9)
	{
		printf("4");
		return 0;
	}
	else
	{
		printf("7");
	}
	return 0;
}

T3

考试题目

#1848. 异或(xor)

考试思路

想到了用

考试代码

// xor
// code by:st20250113
#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1e9 + 10;

int n, q;
int a[MAXN];
int x, y, z;
int l, r;

int lowbit(int k)
{
	return k & (-k);
}

void change(int x, int y)
{
	for (int i = 1; i <= n; i++)
	{
		a[i] = a[i] ^ a[x] ^ y;
	}
	return;
}

int sum(int x)
{
	int ans = 0;
	for (int i = x; i > 0; i -= lowbit(i))
	{
		ans ^= a[i];
	}
	return ans;
}

int main()
{
	freopen("xor.in", "r", stdin);
	freopen("xor.out", "w", stdout);
	scanf("%d %d", &n, &q);
	for (int i = 1; i <= n; i++)
	{
		scanf("%d", &a[i]);
	}
	for (int i = 1; i <= n; i++)
	{
		scanf("%d %d %d", &x, &y, &z);
		if (x == 1)
		{
			change(y, z);
		}
		else
		{
			int ans = 0;
			for (int i = x; i > 0; i -= lowbit(i))
			{
				ans ^= sum(i);
			}
			printf("%d\n",ans);
		}
	}
	return 0;
}