Codeforces Beta Round #77 (Div. 2 Only)

Codeforces Beta Round #77 (Div. 2 Only)

http://codeforces.com/contest/96

A

#include<bits/stdc++.h>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define pb push_back
#define eb emplace_back
#define maxn 13000005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
const long long MOD=1e9+7;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */



int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    string str;
    cin>>str;
    int co=1;
    vector<int>ve;
    for(int i=1;i<str.length();i++){
        if(str[i]!=str[i-1]){
            ve.pb(co);
            co=1;
        }
        else{
            co++;
        }
    }
    ve.pb(co);
    for(int i=0;i<ve.size();i++){
        if(ve[i]>=7) {cout<<"YES"<<endl;return 0;}
    }
    cout<<"NO"<<endl;
}

 

B

dfs+二分

#include<bits/stdc++.h>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define pb push_back
#define eb emplace_back
#define maxn 13000005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
const long long MOD=1e9+7;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */

ll n;

set<ll>se;
map<ll,int>mp;

void Check(ll num){
    ll tmp=num;
    int qi=0,si=0;
    while(num){
        if(num%10==4){
            si++;
        }
        else if(num%10==7){
            qi++;
        }
        num/=10;
    }
    if(si==qi&&si>0){
        se.insert(tmp);
    }
}

void dfs(ll num){
    if(num>n*100000||mp[num]) return;
    mp[num]=1;
    Check(num);
    dfs(num*10+4);
    dfs(num*10+7);
}


int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    cin>>n;
    dfs(0);
    set<ll>::iterator it;
    it=lower_bound(se.begin(),se.end(),n);
    cout<<*it<<endl;
}

 

C

模拟

#include<bits/stdc++.h>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define pb push_back
#define eb emplace_back
#define maxn 13000005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
const long long MOD=1e9+7;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */
const int N = 105;
string s[N], ss[N], w, ww;
bool vis[N];
char str;
string change(string x) {
    for(int i = 0; i < x.length(); i ++) {
        if(x[i] >= 'A' && x[i] <= 'Z') x[i] += 32;
    }
    return x;
}

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    int n;
    cin >> n;
    for(int i = 0; i < n; i ++) {
        cin >> s[i];
        ss[i] = change(s[i]);
    }
    cin >> w >> str;
    ww = change(w);
    if(str >= 'A' && str <= 'Z') str += 32;

    int l = ww.length();
    for(int i = 0; i < l; i ++) {
        for(int k = 0; k < n; k ++) {
            if(l-s[k].length() + 1 >= i && ww.substr(i, ss[k].length()) == ss[k]) {
                for(int j = i; j < i + ss[k].length(); j ++) vis[j] = 1;
            }
        }
    }


    for(int i = 0; i < l; i ++) {
        if(vis[i]) {
            if(ww[i] == str) {
                char tmp = 'a';
                if(ww[i] == 'a') tmp = 'b';

                if(w[i] >= 'A' && w[i] <= 'Z') w[i] = tmp - 32;
                else w[i] = tmp;
            } else {
                if(w[i] >= 'A' && w[i] <= 'Z') w[i] = str - 32;
                else w[i] = str;
            }
        }
    }
    cout << w << endl;
}

 

D

最短路   两次Dijstra 第一次构建以花费为权值的图，第二次跑最短路

#include<bits/stdc++.h>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define pb push_back
#define eb emplace_back
#define maxn 13000005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,int>pli;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
const long long MOD=1e9+7;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */

 int n,m,s,t;

 vector<pli>G[1005],ve[1005];
 vector<pli>a;

 long long dis[1005],vis[1005];

 void dijstra1(int x){
    for(int i=0;i<=n;i++) dis[i]=0x3f3f3f3f3f3f3f3f,vis[i]=0;
    dis[x]=0;
    priority_queue<pli,vector<pli>,greater<pli>>Q;
    Q.push({0,x});
    while(!Q.empty()){
        pli p=Q.top();
        Q.pop();
        int v=p.second;
        if(!vis[v]){
            vis[v]=1;
            for(int i=0;i<G[v].size();i++){
                int vv=G[v][i].second;
                long long dist=G[v][i].first+dis[v];
                if(!vis[vv]&&dist<dis[vv]){
                    dis[vv]=dist;
                    Q.push({dis[vv],vv});
                }
            }
        }
    }
    for(int i=1;i<a.size();i++){
        if(i!=x&&a[x].second>=dis[i]){
            ve[x].pb({a[x].first,i});
        }
    }
 }

 void dijstra2(int x,int t){
    for(int i=0;i<=n;i++) dis[i]=0x3f3f3f3f3f3f3f3f,vis[i]=0;
    dis[x]=0;
    priority_queue<pli,vector<pli>,greater<pli>>Q;
    Q.push({0,x});
    while(!Q.empty()){
        pli p=Q.top();
        Q.pop();
        int v=p.second;
        if(!vis[v]){
            vis[v]=1;
            for(int i=0;i<ve[v].size();i++){
                int vv=ve[v][i].second;
                long long dist=ve[v][i].first+dis[v];
                if(!vis[vv]&&dist<dis[vv]){
                    dis[vv]=dist;
                    Q.push({dis[vv],vv});
                }
            }
        }
    }
    if(dis[t]==0x3f3f3f3f3f3f3f3f) cout<<-1<<endl;
    else cout<<dis[t]<<endl;
 }

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    cin>>n>>m>>s>>t;
    int u,v;
    long long c;
    for(int i=1;i<=m;i++){
        cin>>u>>v>>c;
        G[u].pb({c,v});
        G[v].pb({c,u});
    }
    a.pb({0,0});
    for(int i=1;i<=n;i++){
        cin>>u>>c;
        a.pb({c,u});
    }
    for(int i=1;i<=n;i++){
        dijstra1(i);
    }
    dijstra2(s,t);
}

 

E

大数+数位DP

#include<bits/stdc++.h>
using namespace std;
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define sqr(x) ((x)*(x))
#define pb push_back
#define eb emplace_back
#define maxn 13000005
#define eps 1e-8
#define pi acos(-1.0)
#define rep(k,i,j) for(int k=i;k<j;k++)
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,int>pli;
typedef pair<char,int> pci;
typedef pair<pair<int,string>,pii> ppp;
typedef unsigned long long ull;
const long long mod=1e9+7;
/*#ifndef ONLINE_JUDGE
        freopen("1.txt","r",stdin);
#endif */
const int N=1005;
int digit[N];
ll dp[N][N][2];
char l[N], r[N];
int k;
int dfs(int len, int p, bool flag, bool limit) {
    if (len == 0) return flag;
    if (limit == 0 && dp[len][p][flag] != -1) return dp[len][p][flag];
    int up = limit ? digit[len] : 9;
    int res = 0;
    rep(i, 0, up + 1) {
        if (i != 4 && i != 7)
            res = (res + dfs(len - 1, max(0, p - 1), flag, limit && i == up)) % mod;
        else res = (res + dfs(len - 1, 1 * k, flag || p, limit && i == up)) % mod;
    }
    if (!limit) dp[len][p][flag] = res;
    return res;
}
void solve() {
    int t;
    memset(dp, -1, sizeof dp);
    scanf("%d%d", &t, &k);
    while (t--) {
        scanf("%s%s", l, r);
        int len = strlen(r);
        for(int i=len;i>=0;i--) digit[i] = r[len - i] - '0';
        int ans = dfs(len, 0, 0, 1);
        len = strlen(l);
        for(int i=len;i>=0;i--) digit[i] = l[len - i] - '0';
        digit[1]--;
        for (int i = 1; digit[i] < 0; i++) {
            digit[i] += 10;
            digit[i + 1]--;
        }
        if (digit[len] == 0) len--;
        ans = (ans - dfs(len, 0, 0, 1) + mod) % mod;
        printf("%d\n", ans);
    }
}

int main(){
    #ifndef ONLINE_JUDGE
     //   freopen("1.txt","r",stdin);
    #endif
    std::ios::sync_with_stdio(false);
    solve();
}