gym/101873/GCPC2017

题目链接：https://codeforces.com/gym/101873

C. Joyride

记忆化搜索形式的dp

    #include <algorithm>
    #include  <iterator>
    #include  <iostream>
    #include   <cstring>
    #include   <cstdlib>
    #include   <iomanip>
    #include    <bitset>
    #include    <cctype>
    #include    <cstdio>
    #include    <string>
    #include    <vector>
    #include     <stack>
    #include     <cmath>
    #include     <queue>
    #include      <list>
    #include       <map>
    #include       <set>
    #include   <cassert>
    //#include <unordered_map>
    /*

    ⊂_ヽ
    　 ＼＼ Λ＿Λ  来了老弟
    　　 ＼('ㅅ')
    　　　 >　⌒ヽ
    　　　/ 　 へ＼
    　　 /　　/　＼＼
    　　 ﾚ　ノ　　 ヽ_つ
    　　/　/
    　 /　/|
    　(　(ヽ
    　|　|、＼
    　| 丿 ＼ ⌒)
    　| |　　) /
    'ノ )　　Lﾉ

    */

    using namespace std;
    #define lson (l , mid , rt << 1)
    #define rson (mid + 1 , r , rt << 1 | 1)
    #define debug(x) cerr << #x << " = " << x << "
";
    #define pb push_back
    #define pq priority_queue



    typedef long long ll;
    typedef long double ld;
    typedef unsigned long long ull;
    //typedef __int128 bll;
    typedef pair<ll ,ll > pll;
    typedef pair<int ,int > pii;
    typedef pair<int,pii> p3;

    //priority_queue<int> q;//这是一个大根堆q
    //priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q
    #define fi first
    #define se second
    //#define endl '
'

    #define boost ios::sync_with_stdio(false);cin.tie(0)
    #define rep(a, b, c) for(int a = (b); a <= (c); ++ a)
    #define max3(a,b,c) max(max(a,b), c);
    #define min3(a,b,c) min(min(a,b), c);


    const ll oo = 1ll<<17;
    const ll mos = 0x7FFFFFFF;  //2147483647
    const ll nmos = 0x80000000;  //-2147483648
    const int inf = 0x3f3f3f3f;
    const ll inff = 0x3f3f3f3f3f3f3f3f; //18
    const int mod = 998244353;
    const double esp = 1e-8;
    const double PI=acos(-1.0);
    const double PHI=0.61803399;    //黄金分割点
    const double tPHI=0.38196601;


    template<typename T>
    inline T read(T&x){
        x=0;int f=0;char ch=getchar();
        while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar();
        while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
        return x=f?-x:x;
    }

    inline void cmax(int &x,int y){if(x<y)x=y;}
    inline void cmax(ll &x,ll y){if(x<y)x=y;}
    inline void cmin(int &x,int y){if(x>y)x=y;}
    inline void cmin(ll &x,ll y){if(x>y)x=y;}
    #define MODmul(a, b) ((a*b >= mod) ? ((a*b)%mod + 2*mod) : (a*b))
    #define MODadd(a, b) ((a+b >= mod) ? ((a+b)%mod + 2*mod) : (a+b))

    /*-----------------------showtime----------------------*/
                const int maxn = 1e3+9;
                int dp[maxn][maxn];
                vector<int>mp[maxn];
                int x,n,m,T;
                int tim[maxn],cost[maxn];
                int dfs(int u,int t){
                    if(t > x) return inf;
                    if(dp[u][t]!=-1) return dp[u][t];
                    if(u == 1 && t == x) return dp[u][t] = 0;
                    dp[u][t] = inf;
                    for(int i=0; i<mp[u].size(); i++){
                        int v = mp[u][i];
                        dp[u][t] = min(dp[u][t], dfs(v, t + T + tim[v]) + cost[v]);
                    }
                    dp[u][t] = min(dp[u][t], dfs(u, t+tim[u]) + cost[u]);
                    return dp[u][t];
                }
    int main(){
                memset(dp, -1, sizeof(dp));
                scanf("%d", &x);
                scanf("%d%d%d", &n, &m, &T);
                rep(i, 1, m) {
                    int u,v;    scanf("%d%d", &u, &v);
                    mp[u].pb(v);
                    mp[v].pb(u);
                }
                rep(i, 1, n) {
                    scanf("%d%d", &tim[i], &cost[i]);
                }
                int ans = dfs(1, tim[1]) + cost[1];
                if(ans < inf) printf("%d
", ans);
                else puts("It is a trap.");
                return 0;
    }

E.Perpetuum Mobile

找正环，由于是乘法，所以用log变成加法，还有这题其实是看爱因斯坦那句话，和他助手说的没什么关系，所以要找一个环，环上的乘积大于1，即log >0。于是用spfa判正环就行了。

#include <algorithm>
#include  <iterator>
#include  <iostream>
#include   <cstring>
#include   <cstdlib>
#include   <iomanip>
#include    <bitset>
#include    <cctype>
#include    <cstdio>
#include    <string>
#include    <vector>
#include     <stack>
#include     <cmath>
#include     <queue>
#include      <list>
#include       <map>
#include       <set>
#include   <cassert>
//#include <unordered_map>
/*

⊂_ヽ
　 ＼＼ Λ＿Λ  来了老弟
　　 ＼('ㅅ')
　　　 >　⌒ヽ
　　　/ 　 へ＼
　　 /　　/　＼＼
　　 ﾚ　ノ　　 ヽ_つ
　　/　/
　 /　/|
　(　(ヽ
　|　|、＼
　| 丿 ＼ ⌒)
　| |　　) /
'ノ )　　Lﾉ

*/

using namespace std;
#define lson (l , mid , rt << 1)
#define rson (mid + 1 , r , rt << 1 | 1)
#define debug(x) cerr << #x << " = " << x << "
";
#define pb push_back
#define pq priority_queue



typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
//typedef __int128 bll;
typedef pair<ll ,ll > pll;
typedef pair<int ,int > pii;
typedef pair<int,pii> p3;

//priority_queue<int> q;//这是一个大根堆q
//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q
#define fi first
#define se second
//#define endl '
'

#define boost ios::sync_with_stdio(false);cin.tie(0)
#define rep(a, b, c) for(int a = (b); a <= (c); ++ a)
#define max3(a,b,c) max(max(a,b), c);
#define min3(a,b,c) min(min(a,b), c);


const ll oo = 1ll<<17;
const ll mos = 0x7FFFFFFF;  //2147483647
const ll nmos = 0x80000000;  //-2147483648
const int inf = 0x3f3f3f3f;
const ll inff = 0x3f3f3f3f3f3f3f3f; //18
const int mod = 998244353;
const double esp = 1e-8;
const double PI=acos(-1.0);
const double PHI=0.61803399;    //黄金分割点
const double tPHI=0.38196601;


template<typename T>
inline T read(T&x){
    x=0;int f=0;char ch=getchar();
    while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar();
    while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
    return x=f?-x:x;
}

inline void cmax(int &x,int y){if(x<y)x=y;}
inline void cmax(ll &x,ll y){if(x<y)x=y;}
inline void cmin(int &x,int y){if(x>y)x=y;}
inline void cmin(ll &x,ll y){if(x>y)x=y;}
#define MODmul(a, b) ((a*b >= mod) ? ((a*b)%mod + 2*mod) : (a*b))
#define MODadd(a, b) ((a+b >= mod) ? ((a+b)%mod + 2*mod) : (a+b))

/*-----------------------showtime----------------------*/
typedef  pair<int,double> pid;
            const int maxn = 1e3+9;
            vector<pid>mp[maxn];

            int vis[maxn];
            double dis[maxn];
            queue<int>que;
            bool spfa(int u){
                vis[u] = true;
                for(int i=0; i<mp[u].size(); i++){
                    pid tmp = mp[u][i];
                    int v = tmp.fi;
                    double w = tmp.se;
                    if(dis[v] < dis[u] + w){
                        dis[v] = dis[u] + w;
                        if(vis[v]) return true;
                        if(spfa(v)) return true;
                    }
                }
                vis[u] = false;
                return false;
            }
int main(){
            int n,m;
            scanf("%d%d", &n, &m);
            rep(i, 1, m) {
                int u,v;    double e;
                scanf("%d%d%lf", &u, &v, &e);
                mp[u].pb(pid(v, log(e)));
            }
            for (int i = 1; i <= n; ++i) if(spfa(i)) return 0*puts("inadmissible");
            puts("admissible");
            return 0;
}

H - Ratatoskr 

枚举每个点作为根节点的最大深度，如果这个节点原本就有乌鸦，就只能考虑松鼠所在子树的深度，如果这个节点原本没有乌鸦，就只用考虑这棵树的深度

#include <algorithm>
#include  <iterator>
#include  <iostream>
#include   <cstring>
#include   <cstdlib>
#include   <iomanip>
#include    <bitset>
#include    <cctype>
#include    <cstdio>
#include    <string>
#include    <vector>
#include     <stack>
#include     <cmath>
#include     <queue>
#include      <list>
#include       <map>
#include       <set>
#include   <cassert>
//#include <unordered_map>
/*

⊂_ヽ
　 ＼＼ Λ＿Λ  来了老弟
　　 ＼('ㅅ')
　　　 >　⌒ヽ
　　　/ 　 へ＼
　　 /　　/　＼＼
　　 ﾚ　ノ　　 ヽ_つ
　　/　/
　 /　/|
　(　(ヽ
　|　|、＼
　| 丿 ＼ ⌒)
　| |　　) /
'ノ )　　Lﾉ

*/

using namespace std;
#define lson (l , mid , rt << 1)
#define rson (mid + 1 , r , rt << 1 | 1)
#define debug(x) cerr << #x << " = " << x << "
";
#define pb push_back
#define pq priority_queue



typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
//typedef __int128 bll;
typedef pair<ll ,ll > pll;
typedef pair<int ,int > pii;
typedef pair<int,pii> p3;

//priority_queue<int> q;//这是一个大根堆q
//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q
#define fi first
#define se second
//#define endl '
'

#define boost ios::sync_with_stdio(false);cin.tie(0)
#define rep(a, b, c) for(int a = (b); a <= (c); ++ a)
#define max3(a,b,c) max(max(a,b), c);
#define min3(a,b,c) min(min(a,b), c);


const ll oo = 1ll<<17;
const ll mos = 0x7FFFFFFF;  //2147483647
const ll nmos = 0x80000000;  //-2147483648
const int inf = 0x3f3f3f3f;
const ll inff = 0x3f3f3f3f3f3f3f3f; //18
const int mod = 998244353;
const double esp = 1e-8;
const double PI=acos(-1.0);
const double PHI=0.61803399;    //黄金分割点
const double tPHI=0.38196601;


template<typename T>
inline T read(T&x){
    x=0;int f=0;char ch=getchar();
    while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar();
    while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
    return x=f?-x:x;
}

inline void cmax(int &x,int y){if(x<y)x=y;}
inline void cmax(ll &x,ll y){if(x<y)x=y;}
inline void cmin(int &x,int y){if(x>y)x=y;}
inline void cmin(ll &x,ll y){if(x>y)x=y;}
#define MODmul(a, b) ((a*b >= mod) ? ((a*b)%mod + 2*mod) : (a*b))
#define MODadd(a, b) ((a+b >= mod) ? ((a+b)%mod + 2*mod) : (a+b))

/*-----------------------showtime----------------------*/
            const int maxn = 109;
            vector<int>mp[maxn];
            int dp[maxn],vis[maxn];
            int s,b1,b2,n;
            void dfs(int u,int fa){
                dp[u] = 1;
                if(u == s) vis[u] = 1;
                for(int i=0; i<mp[u].size(); i++){
                    int v = mp[u][i];
                    if(v == fa) continue;
                    dfs(v, u);
                    dp[u] = max(dp[u], dp[v] + 1);
                    if(vis[v]) vis[u] = 1;
                }
            }
int main(){
            scanf("%d%d%d%d", &n, &s, &b1, &b2);
            rep(i, 1, n-1) {
                int u,v;    scanf("%d%d", &u, &v);
                mp[u].pb(v); mp[v].pb(u);
            }
            int ans = inf;
            for(int i=1; i<=n; i++)
            {
                if(i == b1 || i ==b2){
                    memset(vis, 0, sizeof(vis));
                    dfs(i, -1);

                    for(int j=0; j<mp[i].size(); j++) {
                        int v = mp[i][j];
                        if(vis[v]) ans = min(ans, dp[v]);
                    }
                }
                else {
                    dfs(i, -1);
                    ans = min(ans,dp[i]);
                }
            }
            printf("%d
", ans);
            return 0;
}

  J-Word Clock

状压搜索，注意dfs的次序，还有就是只要关了同步，就不能用scanf

#include <algorithm>
#include  <iterator>
#include  <iostream>
#include   <cstring>
#include   <cstdlib>
#include   <iomanip>
#include    <bitset>
#include    <cctype>
#include    <cstdio>
#include    <string>
#include    <vector>
#include     <stack>
#include     <cmath>
#include     <queue>
#include      <list>
#include       <map>
#include       <set>
#include   <cassert>

/*

⊂_ヽ
　 ＼＼ Λ＿Λ  来了老弟
　　 ＼('ㅅ')
　　　 >　⌒ヽ
　　　/ 　 へ＼
　　 /　　/　＼＼
　　 ﾚ　ノ　　 ヽ_つ
　　/　/
　 /　/|
　(　(ヽ
　|　|、＼
　| 丿 ＼ ⌒)
　| |　　) /
'ノ )　　Lﾉ

*/

using namespace std;
#define lson (l , mid , rt << 1)
#define rson (mid + 1 , r , rt << 1 | 1)
#define debug(x) cerr << #x << " = " << x << "
";
#define pb push_back
#define pq priority_queue



typedef long long ll;
typedef unsigned long long ull;
//typedef __int128 bll;
typedef pair<ll ,ll > pll;
typedef pair<int ,int > pii;
typedef pair<int,pii> p3;

//priority_queue<int> q;//这是一个大根堆q
//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q
#define fi first
#define se second
//#define endl '
'

#define boost ios::sync_with_stdio(false);cin.tie(0)
#define rep(a, b, c) for(int a = (b); a <= (c); ++ a)
#define max3(a,b,c) max(max(a,b), c);
#define min3(a,b,c) min(min(a,b), c);


const ll oo = 1ll<<17;
const ll mos = 0x7FFFFFFF;  //2147483647
const ll nmos = 0x80000000;  //-2147483648
const int inf = 0x3f3f3f3f;
const ll inff = 0x3f3f3f3f3f3f3f3f; //18
const int mod = 1e9+7;
const double esp = 1e-8;
const double PI=acos(-1.0);
const double PHI=0.61803399;    //黄金分割点
const double tPHI=0.38196601;


template<typename T>
inline T read(T&x){
    x=0;int f=0;char ch=getchar();
    while (ch<'0'||ch>'9') f|=(ch=='-'),ch=getchar();
    while (ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
    return x=f?-x:x;
}

inline void cmax(int &x,int y){if(x<y)x=y;}
inline void cmax(ll &x,ll y){if(x<y)x=y;}
inline void cmin(int &x,int y){if(x>y)x=y;}
inline void cmin(ll &x,ll y){if(x>y)x=y;}

/*-----------------------showtime----------------------*/
            int n,h,w;
            string str[22],t[22];
            pii dp[20][1<<18],nxt[20][1<<18];
            int dis[22][22];

            pii dfs(int u,int state){
                if(dp[u][state].fi != -1 && dp[u][state].se != -1) return dp[u][state];
                if(state == (1<<n) - 1) return dp[u][state] = pii(1,t[u].length());
                pii ans = pii(inf, inf);

                for(int i=1; i<=n; i++){
                    if(!(state & (1 << (i-1)))) {
                        pii tmp;

                        tmp = dfs(i, state | (1<<(i-1)));

                        int he,wi;
                        int cen = tmp.fi;
                        if(tmp.se + dis[u][i] > w) {
                            he = tmp.fi + 1;
                            wi = t[u].length();
                        }
                        else {
                            he = tmp.fi;
                            wi = tmp.se + dis[u][i];
                        }

                        if(he < ans.fi || (he==ans.fi && ans.se > wi)) {
                            ans.fi = he;    ans.se = wi;
                            nxt[u][state] = pii(i, cen);
                        }
                    }
                }
                return dp[u][state] = ans;
            }
                bool cmp(string a,string b){
                    return a.length() < b.length();
                }
                vector<int> vec[22];
int main(){
                //scanf("%d%d%d", &h, &w, &n);
                boost;
                cin>>h>>w>>n;
                memset(dis, 0, sizeof(dis));
                memset(dp, -1, sizeof(dp));
                int sum = 0;

                for(int i=1; i<=n; i++) cin>>str[i],sum+=str[i].length();
                sort(str+1, str+1+n, cmp);
                int tot = 0;
                for(int i=1; i<=n; i++){
                    if(str[i].length() > w) {
                        puts("impossible");
                        return 0;
                    }
                    int flag = 1;
                    for(int j=i+1; j<=n; j++){
                        if(str[j].find(str[i]) != string::npos) flag = 0;
                    }
                    if(flag) t[++tot] = str[i];
                }
                n = tot;

                for(int i=1; i<=n; i++) {
                    for(int j=1; j<=n; j++){
                        int l1 = t[i].length(), l2 = t[j].length();
                        int len = min(l1, l2);
                        for(int k=0; k<=len; k++){
                            if(t[i].substr(l1-k,k) ==t[j].substr(0, k)) dis[i][j] = l1 - k;
                        }
                    }
                }

                pii tmp = dfs(0, 0);
               // cout<<tmp.fi<<" , "<<tmp.se<<endl;
                if(tmp.fi>h || tmp.se > w) return 0*puts("impossible");

                int st = 0,u = 0;
                while(st < (1<<n) - 1) {
                    int id = nxt[u][st].fi;
                 //   cout<<id<<" "<<nxt[u][st].se<<endl;
                    vec[nxt[u][st].se].pb(id);
                    u = id;
                    st |= (1 << (id - 1));
                }

                for(int i=1; i<=h; i++) {
                    string ans = "";
                    for(int j=0; j<vec[i].size(); j++){
                        string tmp = t[vec[i][j]];
                        int l1 = ans.length(),l2 = tmp.length();
                        int len = min(l1, l2),q;
                        for(int k=0; k<=len; k++){
                            if(ans.substr(l1-k,k) ==tmp.substr(0, k)) q = k;
                        }
                        for(int k=q; k<l2; k++) ans += tmp[k];
                    }
                    while(ans.length() < w) ans += "A";
                    cout<<ans<<endl;
                }

                return 0;
}

/*
5 10 12
ONE TWO THREE FOUR FIVE SIX SEVEN EIGHT NINE TEN ELEVEN TWELVE
5 10 12
UNO DUE TRE QUATTRO CINQUE SEI SETTE OTTO NOVE DIECI UNDICI DODICI
*/