2018浙江省省赛

A

保证先升后降，然后没有不合法的情况，就是Yes

#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define debug  freopen("in.txt","r",stdin),freopen("out.txt","w",stdout);
#define pb push_back
#define all(x) x.begin(),x.end()
#define fs first
#define sc second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn = 1e6+10;
const int maxM = 1e6+10;
const int inf = 0x3f3f3f3f;
const ll inf2 = 0x3f3f3f3f3f3f3f3f;

template<class T>void read(T &x){
    T s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    x = s*w;
}
template<class H, class... T> void read(H& h, T&... t) {
    read(h);
    read(t...);
}
template<class T>void print(T x){
    cout<<x<<" ";
}
template<class H, class... T> void print(H h, T... t) {
    print(h);
    print(t...);
}
int T,N;
int a[maxn];
void solve(){
    int up = 0,down = 0,ok = 1;
    for(int i = 2;i<=N;i++){
        if(a[i] > a[i-1] && down == 0) up = 1;
        else if(a[i] < a[i-1] && up == 1) down = 1;
        else{
            ok = 0;
            break;
        }
    }
    if(ok && up == 1 && down == 1) puts("Yes");
    else puts("No");
}   
int main(){
    // debug;
    read(T);
    while(T--){
        read(N);
        for(int i = 1;i<=N;i++) read(a[i]);
        solve();
    }

    return 0;
}

B

暴力走一遍，记录s[i]-d[i]差值出现最多的次数，输出即可

#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define debug  freopen("in.txt","r",stdin),freopen("out.txt","w",stdout);
#define pb push_back
#define all(x) x.begin(),x.end()
#define fs first
#define sc second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn = 1e6+10;
const int maxM = 1e6+10;
const int inf = 0x3f3f3f3f;
const ll inf2 = 0x3f3f3f3f3f3f3f3f;

template<class T>void read(T &x){
    T s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    x = s*w;
}
template<class H, class... T> void read(H& h, T&... t) {
    read(h);
    read(t...);
}
template<class T>void print(T x){
    cout<<x<<" ";
}
template<class H, class... T> void print(H h, T... t) {
    print(h);
    print(t...);
}
int T,N;
int d[maxn],s[maxn];
map<int,int> mp;
void solve(){
    mp.clear();
    int ans = 0;
    for(int i = 1;i<=N;i++){
        int c = s[i] - d[i];
        mp[c]++;
        ans = max(ans,mp[c]);
    }
    printf("%d\n",ans);
}   
int main(){
    // debug;
    read(T);
    while(T--){
        read(N);
        for(int i = 1;i<=N;i++) read(d[i]);
        for(int i = 1;i<=N;i++) read(s[i]);
        solve();
    }

    return 0;
}

J

sum = n*(n+1)/2
如果sum是奇数，肯定不能分成两部分，输出-1
如果是偶数，就要么n%4 == 3,n%4 == 0
如果n%4 == 1: 1 [2,3,4,5],6 7,2和5，1和6分到G1，G3去
如果n%4 == 0: [1,2,3,4],[5,6,7,8] 1和4，5和8分成到G1,G3去
其余就分配到G2，G4去

#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define debug  freopen("in.txt","r",stdin),freopen("out.txt","w",stdout);
#define pb push_back
#define all(x) x.begin(),x.end()
#define fs first
#define sc second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn = 1e6+10;
const int maxM = 1e6+10;
const int inf = 0x3f3f3f3f;
const ll inf2 = 0x3f3f3f3f3f3f3f3f;

template<class T>void read(T &x){
    T s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    x = s*w;
}
template<class H, class... T> void read(H& h, T&... t) {
    read(h);
    read(t...);
}
template<class T>void print(T x){
    cout<<x<<" ";
}
template<class H, class... T> void print(H h, T... t) {
    print(h);
    print(t...);
}
int T,N;
char s[maxn];
bool vis[100010];
int solve(){
    for(int i = 1;i<=N;i++) vis[i] = 0;
    ll sum = N * (N + 1)/2;
    if(sum %2 == 1) return puts("-1"),0;
    if(N%4 == 3){
        for(int i = 2;i<N-1;i+=4){
            vis[i] = vis[i+3] = 1;
        }
        vis[1] = vis[N-1] = 1;
    }else{
        for(int i = 1;i<=N;i+=4){
            vis[i] = vis[i+3] = 1;
        }
    }
    for(int i =1;i<=N;i++){
        if(s[i] == '1' && vis[i] == 1) printf("3");
        if(s[i] == '0' && vis[i] == 1) printf("1");
        if(s[i] == '1' && vis[i] == 0) printf("4");
        if(s[i] == '0' && vis[i] == 0) printf("2");
    }
    puts("");
    return 0;
}   
int main(){
    // debug;
    read(T);
    while(T--){
        read(N);
        scanf("%s",s+1);
        solve();
    }
    return 0;
}

L

根据公式，(M-i+1)都是正数，且递减，所以单词的喜好度也要是由大到小，这样的结果是最优的

#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define debug  freopen("in.txt","r",stdin),freopen("out.txt","w",stdout);
#define pb push_back
#define all(x) x.begin(),x.end()
#define fs first
#define sc second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn = 1e6+10;
const int maxM = 1e6+10;
const int inf = 0x3f3f3f3f;
const ll inf2 = 0x3f3f3f3f3f3f3f3f;

template<class T>void read(T &x){
    T s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    x = s*w;
}
template<class H, class... T> void read(H& h, T&... t) {
    read(h);
    read(t...);
}
template<class T>void print(T x){
    cout<<x<<" ";
}
template<class H, class... T> void print(H h, T... t) {
    print(h);
    print(t...);
}
int T,N,M;
struct node
{
    string s;
    int v;
    bool operator <(const node &o) const{
        if(v != o.v) return v > o.v;
        else return s < o.s;
    } 
}arr[maxn];
void solve(){
    sort(arr+1,arr+N+1);
    ll ans = 0;
    for(int i = 1;i<=M;i++){
        ans += 1LL * (M-i+1) * arr[i].v;
    }
    cout<<ans<<" ";
    for(int i = 1;i<=M;i++){
        if(i < M) cout<<arr[i].s<<" ";
        else cout<<arr[i].s<<'\n';
    }
}   
int main(){
    // debug;
    ios;

    cin>>T;
    while(T--){
        cin>>N>>M;
        for(int i = 1;i<=N;i++){
            cin>>arr[i].s>>arr[i].v;
        }
        solve();
    }

    return 0;
}

M

暴力走一遍即可

#include <bits/stdc++.h>
#define ios ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define debug  freopen("in.txt","r",stdin),freopen("out.txt","w",stdout);
#define pb push_back
#define all(x) x.begin(),x.end()
#define fs first
#define sc second
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn = 1e6+10;
const int maxM = 1e6+10;
const int inf = 0x3f3f3f3f;
const ll inf2 = 0x3f3f3f3f3f3f3f3f;

template<class T>void read(T &x){
    T s=0,w=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    x = s*w;
}
template<class H, class... T> void read(H& h, T&... t) {
    read(h);
    read(t...);
}
template<class T>void print(T x){
    cout<<x<<" ";
}
template<class H, class... T> void print(H h, T... t) {
    print(h);
    print(t...);
}
int T,N,b;
void solve(){

}   
int main(){
    // debug;
    read(T);
    while(T--){
        read(N,b);
        bool ok = 0;
        for(int i = 1;i<=N;i++){
            int cur;read(cur);
            if((cur + b)%7 == 0)ok = 1;
        }
        if(ok) puts("Yes");
        else puts("No");
    }

    return 0;
}