Codeforces Beta Round #3
http://codeforces.com/contest/3
A
找规律题。但我懒得找，直接暴搜
1 #include<bits/stdc++.h>
2 using namespace std;
3 #define lson l,mid,rt<<1
4 #define rson mid+1,r,rt<<1|1
5 #define sqr(x) ((x)*(x))
6 typedef long long ll;
7 /*#ifndef ONLINE_JUDGE
8 freopen("1.txt","r",stdin);
9 #endif */
10
11 int book[15][15];
12 struct sair{
13 string str[105];
14 int co;
15 int x,y;
16 };
17
18 int dir[8][2]={0,1,1,0,0,-1,-1,0,1,1,-1,-1,1,-1,-1,1};
19 string D[8]={"R","D","L","U","RD","LU","LD","RU"};
20
21 sair bfs(sair s){
22 queue<sair>Q;
23 Q.push(s);
24 sair e;
25 while(!Q.empty()){
26 s=Q.front();
27 Q.pop();
28 for(int i=0;i<8;i++){
29 e=s;
30 e.x=s.x+dir[i][0];
31 e.y=s.y+dir[i][1];
32 if(e.x>=0&&e.x<8&&e.y>=0&&e.y<8&&book[e.x][e.y]!=1){
33 e.str[e.co]=D[i];
34 e.co++;
35 Q.push(e);
36 if(book[e.x][e.y]==2){
37 return e;
38 }
39 book[e.x][e.y]=1;
40 }
41 }
42 }
43 }
44
45 int main(){
46 #ifndef ONLINE_JUDGE
47 freopen("1.txt","r",stdin);
48 #endif
49 string str,str1;
50 cin>>str;
51 sair s;
52 book[7-(str[1]-‘1‘)][str[0]-‘a‘]=1;
53 s.y=str[0]-‘a‘,s.x=7-(str[1]-‘1‘),s.co=0;
54 cin>>str1;
55 book[7-(str1[1]-‘1‘)][str1[0]-‘a‘]=2;
56 if(str==str1) {cout<<0<<endl;return 0;}
57 s=bfs(s);
58 cout<<s.co<<endl;
59 for(int i=0;i<s.co;i++){
60 cout<<s.str[i]<<endl;
61 }
62 }
B
贪心题
因为体积只有1和2两种，所以每次选单位价值最大的物品。需要注意最后容量剩一个的情况，这时候需要对比是选一个好还是把容量为1的物品删去一个再添加一个容量为2的物品好
1 #include<bits/stdc++.h>
2 using namespace std;
3 #define lson l,mid,rt<<1
4 #define rson mid+1,r,rt<<1|1
5 #define sqr(x) ((x)*(x))
6 typedef long long ll;
7 /*#ifndef ONLINE_JUDGE
8 freopen("1.txt","r",stdin);
9 #endif */
10
11 string str;
12 vector<pair<ll,int> >one,two;
13
14 bool cmp(pair<ll,int>a,pair<ll,int>b){
15 if(a.first==b.first) return a.second<b.second;
16 return a.first>b.first;
17 }
18
19 int main(){
20 #ifndef ONLINE_JUDGE
21 freopen("1.txt","r",stdin);
22 #endif
23 ll n,m;
24 cin>>n>>m;
25 int v;
26 ll val;
27 for(int i=1;i<=n;i++){
28 cin>>v>>val;
29 if(v==1){
30 one.push_back(make_pair(val,i));
31 }
32 else{
33 two.push_back(make_pair(val,i));
34 }
35 }
36 sort(one.begin(),one.end(),cmp);
37 sort(two.begin(),two.end(),cmp);
38 int pos1=0,pos2=0;
39 ll ans=0;
40 while(pos1<one.size()||pos2<two.size()){
41 // cout<<pos1<<" "<<pos2<<endl;
42 if(m>=2){
43 if((two[pos2].first/2)>=one[pos1].first&&pos2<two.size()){
44 ans+=two[pos2].first;
45 pos2++;
46 m-=2;
47 }
48 else if(one.size()>pos1){
49 ans+=one[pos1].first;
50 pos1++;
51 m-=1;
52 }
53 else{
54 ans+=two[pos2].first;
55 pos2++;
56 m-=2;
57 }
58 }
59 else if(m==1){
60 if(pos2==two.size()){ans+=one[pos1].first;pos1++;}
61 else if(pos1==one.size()){
62 if(pos1==0)
63 break;
64 else{
65 pos1--;
66 ans-=one[pos1].first;
67 ans+=two[pos2].first;
68 pos2++;
69 }
70 }
71 else if(two[pos2].first>one[pos1-1].first+one[pos1].first){
72 ans-=one[pos1-1].first;
73 pos1--;
74 ans+=two[pos2].first;
75 pos2++;
76 }
77 else{
78 ans+=one[pos1].first;
79 pos1++;
80 }
81 m--;
82 }
83 else if(m==0) break;
84 }
85 cout<<ans<<endl;
86 vector<int>pos;
87 for(int i=0;i<pos1;i++) pos.push_back(one[i].second);
88 for(int i=0;i<pos2;i++) pos.push_back(two[i].second);
89 sort(pos.begin(),pos.end());
90 for(int i=0;i<pos.size();i++){
91 cout<<pos[i]<<" ";
92 }
93 cout<<endl;
94 }
C
井子棋
模拟判断各种情况就好
1 #include<bits/stdc++.h>
2 using namespace std;
3 #define lson l,mid,rt<<1
4 #define rson mid+1,r,rt<<1|1
5 #define sqr(x) ((x)*(x))
6 typedef long long ll;
7 /*#ifndef ONLINE_JUDGE
8 freopen("1.txt","r",stdin);
9 #endif */
10
11 string str[3];
12
13 int Check(){
14 int cha=0,quan=0;
15 if(str[0][0]==str[0][1]&&str[0][1]==str[0][2]&&str[0][0]==‘X‘) cha=1;
16 if(str[1][0]==str[1][1]&&str[1][1]==str[1][2]&&str[1][0]==‘X‘) cha=1;
17 if(str[2][0]==str[2][1]&&str[2][1]==str[2][2]&&str[2][0]==‘X‘) cha=1;
18 if(str[0][0]==str[1][1]&&str[1][1]==str[2][2]&&str[0][0]==‘X‘) cha=1;
19 if(str[0][0]==str[1][0]&&str[1][0]==str[2][0]&&str[0][0]==‘X‘) cha=1;
20 if(str[0][1]==str[1][1]&&str[1][1]==str[2][1]&&str[0][1]==‘X‘) cha=1;
21 if(str[0][2]==str[1][2]&&str[1][2]==str[2][2]&&str[0][2]==‘X‘) cha=1;
22 if(str[0][2]==str[1][1]&&str[1][1]==str[2][0]&&str[0][2]==‘X‘) cha=1;
23
24 if(str[0][0]==str[0][1]&&str[0][1]==str[0][2]&&str[0][0]==‘0‘) quan=1;
25 if(str[1][0]==str[1][1]&&str[1][1]==str[1][2]&&str[1][0]==‘0‘) quan=1;
26 if(str[2][0]==str[2][1]&&str[2][1]==str[2][2]&&str[2][0]==‘0‘) quan=1;
27 if(str[0][0]==str[1][1]&&str[1][1]==str[2][2]&&str[0][0]==‘0‘) quan=1;
28 if(str[0][0]==str[1][0]&&str[1][0]==str[2][0]&&str[0][0]==‘0‘) quan=1;
29 if(str[0][1]==str[1][1]&&str[1][1]==str[2][1]&&str[0][1]==‘0‘) quan=1;
30 if(str[0][2]==str[1][2]&&str[1][2]==str[2][2]&&str[0][2]==‘0‘) quan=1;
31 if(str[0][2]==str[1][1]&&str[1][1]==str[2][0]&&str[0][2]==‘0‘) quan=1;
32 if(quan&&cha) return -1;
33 if(cha) return 1;
34 if(quan) return 2;
35 return 0;
36 }
37
38 int main(){
39 #ifndef ONLINE_JUDGE
40 // freopen("1.txt","r",stdin);
41 #endif
42 ///first second illegal the first player won the second player won draw
43 for(int i=0;i<3;i++) cin>>str[i];
44 int cha=0,quan=0;
45 for(int i=0;i<3;i++) for(int j=0;j<3;j++) if(str[i][j]==‘X‘) cha++; else if(str[i][j]==‘0‘) quan++;
46 if(abs(quan-cha)>=2||quan>cha) cout<<"illegal"<<endl;
47 else{
48 int tmp=Check();
49 if(tmp==-1) cout<<"illegal"<<endl;
50 else if(tmp==1) if(cha>quan) cout<<"the first player won"<<endl;else cout<<"illegal"<<endl;
51 else if(tmp==2) if(quan==cha) cout<<"the second player won"<<endl;else cout<<"illegal"<<endl;
52 else{
53 if(quan+cha==9){
54 cout<<"draw"<<endl;
55 }
56 else if(cha>quan) cout<<"second"<<endl;
57 else if(cha==quan) cout<<"first"<<endl;
58 }
59 }
60 }
D
括号匹配
个人感觉是道好题
先把所有的“？”变成“）”，然后当num<0时，把前面的右括号变成左括号，变的原则是b-a的最大值，最后判断是否括号匹配
1 #include<bits/stdc++.h>
2 using namespace std;
3 #define lson l,mid,rt<<1
4 #define rson mid+1,r,rt<<1|1
5 #define sqr(x) ((x)*(x))
6 typedef long long ll;
7 /*#ifndef ONLINE_JUDGE
8 freopen("1.txt","r",stdin);
9 #endif */
10 struct sair{
11 ll a,b;
12 int pos;
13 bool operator<(const sair&bb)const{
14 return (b-a)<(bb.b-bb.a);
15 }
16 };
17
18 int main(){
19 #ifndef ONLINE_JUDGE
20 freopen("1.txt","r",stdin);
21 #endif
22 string str;
23 cin>>str;
24 ll a,b,ans=0;
25 priority_queue<sair>Q;
26 sair tmp;
27 int num=0;
28 for(int i=0;i<str.length();i++){
29 if(str[i]==‘(‘){
30 num++;
31 }
32 else if(str[i]==‘)‘){
33 num--;
34 }
35 else{
36 cin>>a>>b;
37 tmp.a=a,tmp.b=b,tmp.pos=i;
38 Q.push(tmp);
39 ans+=b;
40 str[i]=‘)‘;
41 num--;
42 }
43 while(num<0){
44 if(Q.size()){
45 ans-=Q.top().b-Q.top().a;
46 str[Q.top().pos]=‘(‘;
47 Q.pop();
48 num+=2;
49 }
50 else{
51 num=-0x3f3f3f3f;
52 break;
53 }
54 }
55 }
56 if(num!=0) cout<<-1<<endl;
57 else{
58 cout<<ans<<endl;
59 cout<<str<<endl;
60 }
61 }
原文地址：https://www.cnblogs.com/Fighting-sh/p/10339466.html
时间： 2024-11-05 23:24:45