AtCoder Beginner Contest 236 题解

A和B和C纯语法题

A、

#include <iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
using namespace std;
typedef long long LL;
int main()
{string s;cin>>s;int l,r;cin>>l>>r;swap(s[l-1],s[r-1]);cout<<s<<endl;return 0;
}

B、

#include <iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<map>
using namespace std;
typedef long long LL;
int main()
{map<int,int> mh;int n;scanf ("%d",&n);for (int i=0;i<n*4-1;i++){int x;scanf ("%d",&x);mh[x]++;}for (auto &[k,v]:mh){if (v!=4){cout<<k<<endl;return 0;}}return 0;
}

C、

#include <iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<set>
#include<vector>
using namespace std;
typedef long long LL;
int main()
{cin.tie(0);set<string> mh;vector<string> ml;int n,m;scanf ("%d%d",&n,&m);for (int i=0;i<n;i++){string s;cin>>s;ml.push_back(s);}for (int i=0;i<m;i++){string s;cin>>s;mh.insert(s);}for (string s:ml){if (mh.count(s))printf ("Yes\n");elseprintf ("No\n");}return 0;
}

D、

直接爆搜所有可能的情况。爆搜的时候时间复杂度是阶乘上升的，应选用好的爆搜写法，不然会TLE。

#include <iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<set>
#include<vector>
#define x first
#define y second
using namespace std;
typedef long long LL;
typedef pair<int,int> PII;
vector<PII> g;
int a[20][20];
int res = 0;
bool st[20];
int n;
void dfs(int u)
{if (u==2*n){int sum = 0;for (int i=0;i<g.size();i++){if (i==0)sum = a[g[i].x][g[i].y-g[i].x-1];elsesum=sum^(a[g[i].x][g[i].y-g[i].x-1]);}res = max(res,sum);return;}if (st[u]) {dfs(u+1);}else{for (int i=u+1;i<2*n;i++){if (!st[i]){g.push_back({u,i});st[i] = true;st[u] = true;dfs(u+1);g.pop_back();st[i] = false;st[u] = false;}   }}}
int main()
{cin.tie(0);memset(st,false,sizeof st);scanf ("%d",&n);for (int i=0;i<2*n-1;i++){for (int j=0;j<2*n-i-1;j++){scanf ("%d",&a[i][j]);// cout<<a[i][j]<<' ';}// cout<<endl;}dfs(0);printf ("%d\n",res);return 0;
}

再把当时TLE的代码粘上,可以对比对比算算复杂度

#include <iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<set>
#include<vector>
#define x first
#define y second
using namespace std;
typedef long long LL;
typedef pair<int,int> PII;
vector<PII> g;
LL a[20][20];
LL res = 0;
bool st[20];
int n;
int cnt =0;
void dfs(int u)
{if (u==n){LL sum = 0;for (int i=0;i<g.size();i++){if (i==0)sum = a[g[i].x][g[i].y-g[i].x-1];elsesum=sum^(a[g[i].x][g[i].y-g[i].x-1]);}res = max(res,sum);return;}for (int i=0;i<2*n;i++)for (int j=i+1;j<2*n;j++){if (!st[i]&&!st[j]){g.push_back({i,j});st[i] = true;st[j] = true;dfs(u+1);g.pop_back();st[i] = false;st[j] = false;}}}
int main()
{cin.tie(0);memset(st,false,sizeof st);scanf ("%d",&n);for (int i=0;i<2*n-1;i++){for (int j=0;j<2*n-i-1;j++){scanf ("%lld",&a[i][j]);}}dfs(0);cout<<res<<endl;return 0;
}

AtCoder Beginner Contest 236 题解相关推荐

AtCoder Beginner Contest 197 题解（A ~ F）
整理的算法模板合集: ACM模板点我看算法全家桶系列!!! 实际上是一个全新的精炼模板整合计划目录 A - Rotate B - Visibility C - ORXOR D - Opposite ...
Caddi Programming Contest 2021(AtCoder Beginner Contest 193) 题解
Caddi Programming Contest 2021(AtCoder Beginner Contest 193) A - Discount 打折浮点数除即可 B - Play Snuke 枚举 ...
Panasonic Programming Contest (AtCoder Beginner Contest 195) 题解
文章目录 A - Health M Death B - Many Oranges C - Comma D - Shipping Center E - Lucky 7 Battle F - Coprim ...
AtCoder Beginner Contest 236 A-D题解
A - chukodai 题意使字符串第a个字符与第b个字符交换` #include<bits/stdc++.h> using namespace std; int dp[109][10 ...
AtCoder Beginner Contest 096 题解
比赛地址 https://abc096.contest.atcoder.jp A - Day of Takahashi 题目大意我们把月和日相同的日期叫做"Takahashi日" ...
freee Programming Contest 2022(AtCoder Beginner Contest 264) 题解 (A~D)
A - "atcoder".substr() Time Limit: 2 sec / Memory Limit: 1024 MB Score : 100100100 points ...
[2021-09-04 AtCoder Beginner Contest 217] 题解
文章目录 A - Lexicographic Order B - AtCoder Quiz C - Inverse of Permutation D - Cutting Woods E - Sorti ...
AtCoder Beginner Contest 168题解
这里写目录标题 A - ∴ (Therefore) 代码 B - ... (Triple Dots) 代码 C - : (Colon) 代码 D - .. (Double Dots) 题意题解代码 ...
AtCoder Beginner Contest 153 题解
题解链接:题解链接 RD是输入,OT是输出 A – SERVAL VS MONSTER 链接: A题题意: 给你怪物血量H和攻击一次扣A血,问至少要攻击几次能使怪物的血量小于或者等于0 解法: 按题 ...
AtCoder Beginner Contest 177 题解
希望更好的阅读体验?点这里一.题解 A.Don't be late 题目大意: 高桥君计划在 TTT 分钟内于离家 DDD 米的地方与青木君碰面,已知高桥君速度为 SSS,问他能否在 TTT 分钟内 ...

AtCoder Beginner Contest 236 题解

A、

B、

C、

D、

AtCoder Beginner Contest 236 题解相关推荐

最新文章

热门文章