程设2022期末

A.最长下坡

#include <cstdio>

int a[1000];

int main(){
	int n, ans = 0, now = 0;scanf("%d", &n);
	for(int i = 1; i <= n; ++i){
		int x;scanf("%d", &x);a[i] = a[n + i] = x;
	}
	for(int i = 2; i <= n * 2; ++i){
		if (a[i] < a[i - 1]) ++now;
		else{
			if (now > ans) ans = now;
			now = 0;
		}
	}
	printf("%d\n", ans);
	return 0;
}

B.斗地主大师

#include <iostream>
#include <cstdio>

using namespace std;

long long inf = 1000000000;
long long p, q, x, y, ans = inf;

void dfs(long long now, long long cnt){
	if (cnt > 52) return;
	if (now == p){
		ans = min(ans, cnt);
		return;
	}
	if (now % y == 0) dfs(now / y, cnt + 1);
	dfs(now + x, cnt + 1);
}

int main(){
	cin>>p>>q>>x>>y;
	dfs(q, 0);
	if (ans == inf) cout<<"Failed"<<endl;
	else cout<<ans<<endl;
	return 0;
}

C.通配符匹配

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

bool f(string s, string p){
	int len = s.length();
	for (int i = 0; i < len; ++i){
		if (p[i] == s[i]);
		else if (p[i] == '?');
		else if(p[i] != '*') return false;
		else{
			int tmp = i;
			while (p[tmp] == '*') ++tmp;
			for (int j = i; j <= len; ++j)
				if (f(s.substr(j, len - j), p.substr(tmp, len - tmp)))
					return true;
			return false;
		}
	}
	if(p.length() == len) return true;
	return false;
}

int main(){
	int T;cin>>T;while(T--){
		string s, p;cin>>s>>p;
		if (f(s, p)) cout<<"yes"<<endl;
		else cout<<"no"<<endl;
	}
	return 0;
}

D.薅羊毛

用背包的思想，f数组记录到达 f[i] 有几种方法，g数组记录当前这一步从哪里转移。
（感谢lyt倾情讲解orz

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int inf = 1000000000;
int n, m, maxx = inf, num;
int a[2000], f[50000], g[50000];

void print(int i){
	cout<<i<<' '<<f[i]<<endl;
	vector<int> v;
	for (int j = i; j; j = g[j]){
		v.push_back(j);
	}
	int sum = 0, cnt = 1;
	while (!v.empty()){
//		cout<<v.back()<<' ';v.pop_back();
		int now = v.back() - sum;v.pop_back();
		while (a[cnt] != now) ++cnt;
		cout<<cnt<<' ';sum += now;
	}
	cout<<endl;
}

signed main(){
	cin>>n>>m;
	for (int i = 1; i <= n; ++i){
		cin>>a[i];
		if (a[i] < m) continue;
		if (a[i] == maxx) ++num;
		if (a[i] < maxx) num = 1, maxx = a[i];
	}
	f[0] = 1;
	for (int i = 1; i <= n; ++i){
		for (int j = m * 2 - 1; j >= a[i]; --j){
			if (f[j - a[i]]){
				f[j] += f[j - a[i]];
				g[j] = j - a[i];
			}
		}
	}
	for (int i = m; i < m * 2; ++i){
		if (f[i]){
			if (f[i] == 1) print(i);
			else cout<<i<<' '<<f[i]<<endl;
			return 0;
		}
	}
	if (num == inf) cout<<0<<endl;
	else cout<<num<<endl;
	return 0;
}

F.发放年终奖

#include <cstdio>
#include<iostream>
#include<algorithm>
using namespace std;

int a[200000];

int main(){
	int T;cin>>T;while(T--){
		int n, k, cnt = 1, b = 0;cin>>n>>k;
		for(int i = 1;i <= n;++i){
			cin>>a[i];
		}
		sort(a + 1, a + n + 1);
		for(int i = n - 1; i >= 1; --i){
			if (k >= a[n] - a[i]){
				k -= a[n] - a[i];
				++cnt;
			}
			else{
				cout<<cnt<<endl;
				b = 1;break;
			}
		}
		if(!b) cout<<n<<endl;
	}
	return 0;
}