include <bits/stdc++.h> // 万能头文件 ios::sync_with_stdio(false); cin.tie(0); 加速c++输入输出流
setprecision() 浮点数从做到右一共能输出几个数字，但小数末尾为0则不能输出
fix 保留几位小数 cout.setf(ios::fixed);
showpoint cout.setf(ios::showpoint); 输出小数末尾的0
C：
1 #include <iostream> 2 #include <cstdio> 3 4 using namespace std; 5 int main() 6 { 7 double n, sum = 0, tem = 0; 8 int a[100000] = {0}; 9 int b = 1, k, v; 10 cin >> n >> k; 11 for (int i = 0; i < n; i++) 12 { 13 cin >> a[i]; 14 } 15 16 for (int i = 0; i <= n - k; i++) 17 { 18 b = 0; 19 sum = 0; 20 v = k; 21 for (int j = i; j < k + i; j++) 22 { 23 sum += a[j]; 24 } 25 if (sum / (k + b) > tem) 26 { 27 tem = sum / (k + b); 28 } 29 while (v < n) 30 { 31 sum = sum + a[k + i + b]; 32 b++; 33 if (sum / (k + b) > tem) 34 tem = sum / (k + b); 35 v++; 36 } 37 } 38 printf ("%.15lf", tem); 39 40 return 0; 41 }
- 在程序设计的时候比下一种做法更有技巧：每次从k增加一个数
1 #include <bits/stdc++.h> 2 3 using namespace std; 4 5 int main() { 6 ios_base::sync_with_stdio(0); 7 cin.tie(NULL); 8 double s = 0; 9 long long n, k, i, l, r, tmp; 10 cin >> n >> k; 11 vector<long long> a(n); 12 for(i=0;i<n;i++) cin >> a[i]; 13 14 for(l = 0; l < n; l++) { 15 tmp = 0; 16 for(r = l; r < n; r++) { 17 tmp += a[r]; 18 if(r-l+1 >= k) { 19 s = max(s, double(tmp /1.0 / (r-l+1))); 20 } 21 } 22 } 23 24 cout << setprecision(10) << fixed << s; 25 return 0; 26 }
- 换了个编译器就好使了？？？
D
1 #include<stdio.h> 2 #include<map> 3 using namespace std; 4 map<int,int> mp; 5 struct{ 6 int sm; 7 }st[35]; 8 int mn; 9 int s[35]; 10 void init(){ 11 int i,a; 12 a=1; 13 mp[1]=0; 14 st[0].sm=1; 15 for(i=1;i<=31;i++){ 16 a=a*2; 17 mp[a]=i; 18 st[i].sm=a; 19 } 20 } 21 int min(int a,int b){ 22 if(a<b) 23 return a; 24 return b; 25 } 26 int dfs(int k,int j,int cnt){ 27 int i; 28 if(j<0){ 29 if(k==0) 30 mn=cnt; 31 return 0; 32 } 33 i=min(k/st[j].sm,s[mp[st[j].sm]]); 34 dfs(k-i*st[j].sm,j-1,cnt+i); 35 return 0; 36 } 37 int main(){ 38 init(); 39 int n,q; 40 int i,j,a; 41 scanf("%d%d",&n,&q); 42 for(i=0;i<n;i++){ 43 scanf("%d",&a); 44 s[mp[a]]++; 45 } 46 while(q--){ 47 mn=0; 48 scanf("%d",&a); 49 dfs(a,31,0); 50 if(mn==0) 51 printf("-1 "); 52 else 53 printf("%d ",mn); 54 } 55 return 0; 56 }
- 我的常规DFS做法，中间调试了很久，因为我对这个过程还是不是特别了解。并没有掉到坑里之后永远见到这个坑绕道走。
- 还是超时了呵呵哒
1 #include <iostream> 2 #include <cstdio> 3 4 using namespace std; 5 int a[1000001]; 6 int n,q,num,best; 7 void dfs(int i,int count1,int sum) // 第i个硬币选或不选，count为选择硬币个数，sum为硬币的和 8 { 9 if (i == n || sum == num) 10 { 11 if (sum==num &&count1 < best) 12 { 13 best = count1; 14 return ; 15 } 16 return ; // 很关键！ 17 18 } 19 if (sum > num) 20 return ; 21 if (sum+a[i] <= num) 22 { 23 // 选择该硬币 24 dfs(i+1,count1+1,sum+a[i]); 25 } 26 // 不选择该硬币 27 dfs(i+1,count1,sum); 28 } 29 int main() 30 { 31 32 while (scanf("%d%d",&n,&q)!=EOF) 33 { 34 for (int i=0;i<n;i++) 35 scanf("%d",&a[i]); 36 for (int i=0;i<q;i++) 37 { 38 scanf("%d",&num); 39 best = 65515; 40 dfs(0,0,0); 41 if (best == 65515) 42 cout << -1 <<endl; 43 else 44 cout << best << endl; 45 46 } 47 48 49 } 50 51 return 0; 52 } 53
- 我重新做了一遍
1 #include<stdio.h> 2 #include<map> 3 #include <iostream> 4 #include <string> 5 #include <string.h> 6 using namespace std; 7 8 map<int,int> mp; 9 int rmap[32]; 10 int s[32]; 11 int bst; //最小的 12 void init() 13 { 14 int a = 1; 15 mp[a] = 0; 16 rmap[0] = a; 17 for (int i = 1;i<=31;i++) 18 { 19 a*=2; 20 mp[a] = i; 21 rmap[i]=a; 22 } 23 // for (int i=0;i<32;i++) 24 // cout << i <<' '<<rmap[i] << endl; 25 } 26 void dfs(int sum,int level,int cnt) 27 { 28 if (level < 0) 29 { 30 if (sum==0) 31 { 32 bst = cnt; // 一定是最小的方案 33 } 34 return ; 35 } 36 int i = min(sum/rmap[level],s[level]); 37 dfs(sum-i*rmap[level],level-1,cnt+i); 38 } 39 int main(){ 40 41 int n,q,a,cnt; 42 cin >> n >>q; 43 memset(s,0,sizeof(s)); 44 memset(rmap,0,sizeof(rmap)); 45 mp.clear(); 46 init(); 47 48 for (int i=0;i<n;i++) 49 { 50 cin >> a; 51 s[mp[a]]++; 52 } 53 while (q--) 54 { 55 cin >> a; 56 bst = 0; 57 dfs(a,31,0); // cnt为数字的个数 58 if (bst==0) 59 cout << -1 << endl; 60 else 61 cout << bst << endl; 62 } 63 64 return 0; 65 }
E
1 #include <iostream> 2 #include <vector> 3 #include <algorithm> 4 #include <string> 5 6 #define all(a) a.begin(), a.end() 7 #define forn(a, b) for(int a = 0; a < b; a++) 8 #define from(a, b, c) for(int a = b; a < c; a++) 9 #define KEK cout << "KEK "; 10 11 using namespace std; 12 13 14 int n, d, k; 15 int ptr = 2; 16 17 vector< vector < int > > tree(1000000); 18 19 int deep[1000000]; 20 int mark[1000000]; 21 22 bool first_chek() { 23 if((n - 1) < d) 24 return true; 25 26 if(k == 1 && d != (n - 1)) 27 return true; 28 29 return false; 30 } 31 32 void first_step() { 33 //KEK 34 int a, b, top = 1; 35 36 if(k == 1) { 37 a = 1; 38 b = 0; 39 } else { 40 a = d / 2; 41 b = (d + 1) / 2; 42 } 43 44 //cout << " :: " << a << " " << b << endl; 45 //KEK 46 forn(i, a) { 47 tree[top].push_back(ptr); 48 deep[ptr] = deep[top] + 1; 49 top = ptr; 50 ptr++; 51 } 52 //KEK 53 top = 1; 54 forn(i, b) { 55 if(d % 2 == 1 && top != 1)mark[top] = 1; 56 tree[top].push_back(ptr); 57 deep[ptr] = deep[top] + 1; 58 top = ptr; 59 ptr++; 60 61 } 62 //KEK 63 } 64 65 void second_step(){ 66 //KEK 67 for(int i = 1; i < ptr && i <= n; i++) { 68 //cout << i << endl; 69 if(deep[i] + 1 > d / 2) { 70 if(mark[i] == 0) 71 continue; 72 else 73 mark[i] = 0; 74 } 75 if(ptr > n) 76 return; 77 //cout << "1:: " << i << " " << tree[i].size() << endl; 78 for(int j = tree[i].size(); j < k - (i != 1 ? 1 : 0); j++) { 79 if(ptr > n) 80 return; 81 tree[i].push_back(ptr); 82 deep[ptr] = deep[i] + 1; 83 mark[ptr] = mark[i]; 84 ptr++; 85 } 86 } 87 } 88 89 90 int main() { 91 92 cin >> n >> d >> k; 93 94 if(first_chek()){ 95 cout << "NO "; 96 return 0; 97 } 98 99 first_step(); 100 101 second_step(); 102 103 //KEK 104 105 //cout << ptr << endl; 106 107 if(ptr <= n) 108 cout << "NO "; 109 else { 110 cout << "YES "; 111 for(int i = 1; i <= n; i++) { 112 for(int j = 0; j < tree[i].size(); j++) { 113 cout << i << " " << tree[i][j] << endl; 114 } 115 } 116 } 117 118 }
1 #include <iostream> 2 #include <bits/stdc++.h> 3 4 using namespace std; 5 6 int main() 7 { 8 int n, d, k; 9 cin >> n >> k >> d; 10 if(n - 1 < k)return cout << "NO", 0; 11 12 if(d == 1 || n == 2 || k == 1){ 13 if(n == 2 && k == 1 && d >= 1) cout << "YES 1 2"; 14 else cout << "NO"; 15 return 0; 16 } 17 vector<vector<int> > edges(n); 18 int currNode = 1; 19 20 for(int i=1;i<=ceil(k * 0.5);i++){ 21 edges[i - 1].push_back(i); 22 currNode++; 23 } 24 25 int stopNode1 = currNode - 1; 26 edges[0].push_back(currNode); 27 currNode++; 28 for(int i=1;i<k/2;i++){ 29 edges[currNode - 1].push_back(currNode); 30 currNode++; 31 } 32 int stopNode2 = currNode - 1; 33 queue<int> q; 34 q.push(0); 35 while(!q.empty() && currNode != n){ 36 int node = q.front(); q.pop(); 37 for(int ch : edges[node]){ 38 q.push(ch); 39 } 40 if(node == stopNode1 || node == stopNode2)break; 41 while(edges[node].size() + (node != 0) < d && currNode != n){ 42 edges[node].push_back(currNode); 43 q.push(currNode); 44 currNode++; 45 } 46 } 47 48 49 if(currNode != n)cout << "NO"; 50 else{ 51 cout << "YES "; 52 for(int i=0;i<n;i++){ 53 for(int ch : edges[i]){ 54 cout << i + 1 << " " << ch + 1 << endl; 55 } 56 } 57 } 58 return 0; 59 }
F
1 #include<bits/stdc++.h> 2 3 using namespace std; 4 5 map<string,int>mp; 6 7 int main() { 8 int n,id=0; 9 string tmp; 10 vector<int> a(n+1),b(n+1); 11 12 cin>>n; 13 // 统计每一个单词的个数，a[i]存放第i个位置的字符串的相同串的个数 14 for(int i=1;i<=n;i++){ 15 cin>>tmp; 16 if(mp[tmp]==0) mp[tmp]=++id; 17 a[i]=mp[tmp]; 18 b[i]=tmp.length()+b[i-1]; // 统计串的长度 19 } 20 21 int cnt=b.back()+n-1,ans=cnt; // 字符串中非空格串长度+空格的个数，ans默认为这个 22 23 for(int i=1;i<=n;i++){ 24 for(int j=i;j<=n;j++){ 25 int len=1-(b[j]-b[i-1]),ct=0; 26 for(int k=j+1;k+j-i<=n;k++){ 27 int flag=1; 28 for(int p=0;p<j-i+1;p++){ 29 if(a[i+p]!=a[k+p]){ 30 flag=0;break; 31 } 32 } 33 if(flag){ 34 ct++;k=k+j-i; 35 } 36 } 37 if(ct){ 38 ans=min(ans,cnt+(ct+1)*len); 39 } 40 } 41 } 42 43 cout<<ans<<endl; 44 }