山东省2016acm省赛

A

水

 #include <iostream>
 #include <cstdio>
 #include <algorithm>
 #include <list>
 #include <map>
 #include <stack>
 #include <vector>
 #include <cstring>
 #include <sstream>
 #include <string>
 #include <cmath>
 #include <queue>
 using namespace std;
 #define clc(a,b) memset(a,b,sizeof(a))
 #define inf 0x3f3f3f3f
 const int N=;
 const int MOD = 1e9+;
 #define LL long long
 void fre() {
     freopen("in.txt","r",stdin);
 }
 inline int r() {
     int x=,f=;char ch=getchar();
     while(ch>''||ch<'') {if(ch=='-') f=-;ch=getchar();}
     while(ch>=''&&ch<='') { x=x*+ch-'';ch=getchar();}return x*f;
 }

 int main(){
     int T;
     T=r();
     while(T--){
         int x,y;
         int ans;
         x=r();
         y=r();
         if(x%y!=)
             ans=x/y+;
         else
             ans=x/y;
         cout<<ans<<endl;
     }
     return ;
 }

C

最短路

反向建边，记录当前点序号最小的前驱

 #include <iostream>
 #include <cstdio>
 #include <algorithm>
 #include <list>
 #include <map>
 #include <stack>
 #include <vector>
 #include <cstring>
 #include <sstream>
 #include <string>
 #include <cmath>
 #include <queue>
 #include <bits/stdc++.h>
 using namespace std;
 #define clc(a,b) memset(a,b,sizeof(a))
 #define inf 0x3f3f3f3f
 const int N=;
 const int MOD = 1e9+;
 #define LL long long
 void fre() {
     freopen("in.txt","r",stdin);
 }
 inline int r() {
     int x=,f=;char ch=getchar();
     while(ch>''||ch<'') {if(ch=='-') f=-;ch=getchar();}
     while(ch>=''&&ch<='') { x=x*+ch-'';ch=getchar();}return x*f;
 }
 int n,m;
 struct node{
     int v,c;
     node(int vv,int cc){
        v=vv;
        c=cc;
     }
     node(){}
     bool operator <(const node &r) const{
         return c>r.c;
     }
 };

 struct edge{
     int v,cost;
     edge(int vv=,int ccost =):v(vv),cost(ccost){}
 };

 vector<edge>e[N];
 bool vis[N];
 int dist[N];
 int p[N];
 void dij(int start){
     clc(vis,false);
     for(int i=;i<=n+;i++) dist[i]=inf;
     priority_queue<node>q;
     while(!q.empty()) q.pop();
     dist[start]=;
     q.push(node(start,));
     node tmp;
     while(!q.empty()){
         tmp=q.top();
         q.pop();
         int u=tmp.v;
         if(vis[u]) continue;
         vis[u]=true;
         for(int i=;i<e[u].size();i++){
              int v=e[u][i].v;
              int cost=e[u][i].cost;
              if(!vis[v]&&dist[v]>dist[u]+cost){
                 dist[v]=dist[u]+cost;
                 p[v]=u;
                 q.push(node(v,dist[v]));
              }
              else if(!vis[v]&&dist[v]==dist[u]+cost){
                 p[v]=min(p[v],u);
              }
         }
     }
 }
 void add(int u,int v,int w){
     e[u].push_back(edge(v,w));
 }

 void init(){
     for(int i=;i<=n+;i++){
         e[i].clear();
     }
     clc(p,-);
 }

 int main(){
     // fre();
     int T;
     T=r();
     while(T--){
         n=r(),m=r();
         init();
         int u,v,w;
         while(m--){
             u=r(),v=r(),w=r();
             add(v,u,w);
         }
         dij(n+);
         if(dist[]>=inf){
             printf("-1\n");
             continue;
         }
         else if(p[]==n+){
             printf("0\n");
             continue;
         }
         else
             printf("%d\n",p[]);
     }
     return ;
 }

D

归并排序技巧题

 #include <iostream>
 #include <cstdio>
 #include <algorithm>
 #include <list>
 #include <map>
 #include <stack>
 #include <vector>
 #include <cstring>
 #include <sstream>
 #include <string>
 #include <cmath>
 #include <queue>
 using namespace std;
 #define clc(a,b) memset(a,b,sizeof(a))
 #define inf 0x3f3f3f3f
 const int N=;
 const int MOD = 1e9+;
 #define LL long long
 void fre() {
     freopen("in.txt","r",stdin);
 }
 inline int r() {
     int x=,f=;char ch=getchar();
     while(ch>''||ch<'') {if(ch=='-') f=-;ch=getchar();}
     while(ch>=''&&ch<='') { x=x*+ch-'';ch=getchar();}return x*f;
 }
 struct node{
     int s,w,num;
 }p[N];
 int n,R,q;
 node a[N],b[N];

 bool cmp(const node &a,const node &b){
    return (a.s==b.s)?(a.num<b.num):(a.s>b.s);
 }

 void work(){
     int ai=,bi=;
     for(int i=;i<=*n;i+=){
         if(p[i].w>p[i+].w){
             p[i].s++;
             a[ai++]=p[i];
             b[bi++]=p[i+];
         }
         else{
             p[i+].s++;
             a[ai++]=p[i+];
             b[bi++]=p[i];
         }
     }
     int i=,j=,k=;
     while(i<ai&&j<bi){
         if(cmp(a[i],b[j])){
             p[k++]=a[i++];
         }
         else
             p[k++]=b[j++];
     }
     while(i<ai) p[k++]=a[i++];
     while(j<bi) p[k++]=b[j++];
 }

 int main(){
     // fre();
     int T;
     T=r();
     while(T--){
          n=r(),R=r(),q=r();
          for(int i=;i<=*n;i++){
             int x;
             x=r();
             p[i].s=x;
             p[i].num=i;
          }
          for(int i=;i<=*n;i++){
             int x;
             x=r();
             p[i].w=x;
          }
          sort(p+,p++*n,cmp);
          for(int i=;i<=R;i++){
             work();
          }
          printf("%d\n",p[q].num);
     }
     return ;
 }

F

dp记忆话搜索

dp[i][j][k][inx][last]:当前三种水果分别有i j k个的时候且当前放第inx类的水果，持续了last天的方案数

 #include <iostream>
 #include <cstdio>
 #include <algorithm>
 #include <list>
 #include <map>
 #include <stack>
 #include <vector>
 #include <cstring>
 #include <sstream>
 #include <string>
 #include <cmath>
 #include <queue>
 using namespace std;
 #define clc(a,b) memset(a,b,sizeof(a))
 #define inf 0x3f3f3f3f
 const int N=;
 const int MOD = 1e9+;
 #define LL long long
 void fre() {
     freopen("in.txt","r",stdin);
 }
 inline int r() {
     int x=,f=;char ch=getchar();
     while(ch>''||ch<'') {if(ch=='-') f=-;ch=getchar();}
     while(ch>=''&&ch<='') { x=x*+ch-'';ch=getchar();}return x*f;
 }

 int num;
 int dp[][][][][];
 int a[],b[];

 int dfs(int n,int a0,int a1,int a2,int inx,int last){
     LL ans=;
     if(dp[a0][a1][a2][inx][last]!=-) return dp[a0][a1][a2][inx][last];
     if(n==num) return dp[a0][a1][a2][inx][last]=;
     if(inx==-){
        if(b[]>&&a0>=) ans+=dfs(n+,a0-,a1,a2,,);
        if(b[]>&&a1>=) ans+=dfs(n+,a0,a1-,a2,,);
        if(b[]>&&a2>=) ans+=dfs(n+,a0,a1,a2-,,);
     }
     else{
        if(inx==){
           if(last+<=b[]&&a0>=) ans+=dfs(n+,a0-,a1,a2,,last+);
           if(b[]>&&a1>=) ans+=dfs(n+,a0,a1-,a2,,);
           if(b[]>&&a2>=) ans+=dfs(n+,a0,a1,a2-,,);
         }
        else if(inx==){
           if(last+<=b[]&&a1>=) ans+=dfs(n+,a0,a1-,a2,,last+);
           if(b[]>&&a0>=) ans+=dfs(n+,a0-,a1,a2,,);
           if(b[]>&&a2>=) ans+=dfs(n+,a0,a1,a2-,,);
        }
        else{
           if(last+<=b[]&&a2>=) ans+=dfs(n+,a0,a1,a2-,,last+);
           if(b[]>&&a0>=) ans+=dfs(n+,a0-,a1,a2,,);
           if(b[]>&&a1>=) ans+=dfs(n+,a0,a1-,a2,,);
        }
     }
     ans%=MOD;
     return dp[a0][a1][a2][inx][last]=ans;
 }

 int main(){
     int T;
     T=r();
     while(T--){
        clc(dp,-);
        for(int i=;i<;i++){
           // scanf("%d",&a[i]);
           int x;
           x=r();
           a[i]=x;
        }
        for(int i=;i<;i++){
            // scanf("%d",&b[i]);
            int x;
            x=r();
            b[i]=x;
        }
        num=a[]+a[]+a[];
        printf("%d\n",dfs(,a[],a[],a[],-,));
     }
     return ;
 }