North America Qualifier (2015)

https://icpc.baylor.edu/regionals/finder/north-america-qualifier-2015

一个人打。。。。

B

概率问题公式见代码

 #include <cstdio>
 #include <cstring>
 #include <iostream>
 #include <queue>
 #include <stack>
 #include <vector>
 #include <algorithm>
 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 countt;
 int  comb1(int m,int k)
 {
     int i;
     for (i=m;i>=k;i--)
     {
         if (k>)
         {
             comb1(i-,k-);
         }
         else
         {
             countt++;
         }
     }
     return countt;
 }

 int main(){
     // fre();
     int T;
     int R,s,x,y,w;
     T=r();
     while(T--){
         double p1=0.0;
         int num;
        cin>>R>>s>>x>>y>>w;
        double p=(s-R+)*1.0/s;
        double ans=0.0;
        for(int i=x;i<=y;i++){
            int c=y-i;
            p1=1.0;
            double p2=1.0-p;
            while(c--){
                p1*=p2;
            }
            int cc=i;
            double P=1.0;
            for(int j=;j<=i;j++){
               P*=p;
            }
            // cout<<i<<" "<<P<<endl;
            countt=;
            num=comb1(y,i);
            // cout<<P<<" "<<p1<<" "<<num<<endl;
           ans+=P*p1*num;
        }
        // cout<<ans<<endl;
        if(ans*w>)
         printf("yes\n");
        else
         printf("no\n");
     }
     return ;
 }

F

水题

输出字符串中缺少的字母

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<queue>
 #include<stack>
 #include<algorithm>
 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=0,f=1;char ch=getchar();
 //     while(ch>'9'||ch<'0'){if(ch=='-') f=-1;ch=getchar();}
 //     while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
 //     return x*f;
 // }
 int a[];
 char ans[];
 int main()
 {

     int T;
     scanf("%d",&T);
     getchar();
     while(T--)
     {
         clc(a,);
         clc(ans,);
         string s;
         getline(cin,s);
         for(int i = ; i < s.length(); i ++){
             if(s[i] >= 'a' && s[i] <= 'z')
             a[s[i] - 'a'] ++;
             if(s[i] >= 'A' && s[i] <= 'Z')
             a[s[i] - 'A'] ++;
         }
         int k = ;
         for(int i  = ; i < ; i ++){
             if(!a[i]){
                 ans[k++] = i + 'a';
             }
         }
         if(k ==) {
             printf("pangram\n");
         }
         else{
             printf("missing ");
             for(int i = ; i< k;  i ++){
                 printf("%c",ans[i]);
             }
             printf("\n");
         }
     }
     return ;
 }

G

过河的经典问题

多个人过河每次船上必须有一人问最短时间

 #include <cstdio>
 #include <cstring>
 #include <iostream>
 #include <queue>
 #include <stack>
 #include <vector>
 #include <algorithm>
 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 TravelBridge(std::vector<int> times)
 {
     size_t length = times.size();
     if(length <= )
         return times[length-];
     else if(length == )
     {
         return times[] + times[] + times[];
     }
     else
     {
         int totaltime = ;
         int a = times[];
         int b = times[];
         int z = times[length-];
         int y = times[length-];
         if(b* < a + y)
         {
             times.erase(times.end()-);
             times.erase(times.end()-);
             totaltime += b + a + z + b + TravelBridge(times);
         }
         else
         {
             times.erase(times.end()-);
             totaltime += z + a + TravelBridge(times);
         }
         return totaltime;
     }
 }

 int main(){
     int n;
     n=r();
     vector<int> v;
     for(int i=;i<n;i++){
         int x;
         x=r();
         v.push_back(x);
     }
     sort(v.begin(),v.end());
     int ans=TravelBridge(v);
     printf("%d\n",ans);
     return ;
 }

H

水题

旋转矩阵再输出

 #include<cstdio>
 #include<cstring>
 #include<iostream>
 #include<queue>
 #include<stack>
 #include<algorithm>
 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;
 }

 char s[];
 char a[][];
 int main() {
     // fre();
     int T;
     T=r();
     // getchar();
     while(T--) {
         scanf("%s",s);
         int len = strlen(s);
         int q = ;
         for(; ; q ++) {
             if(q * q >= len) {
                 break;
             }
         }
         // cout<<s[0]<<endl;
         int pos;
         for(int i = ; i < q; i ++) {
             for(int j = ; j < q ; j ++) {
                 pos = i * q + j;
                 if(pos >= len) {
                     a[i][j] = '*';
                 } else {
                     a[i][j] = s[pos];
                 }
             }
         }
         // printf("%c\n",a[0][0]);
         // for(int i=0;i<q;i++){
         //     for(int j=0;j<q;j++){
         //         printf("%c ",a[i][j]);
         //     }
         //     printf("\n");
         // }
         for(int j = ; j < q ; j ++) {
             for(int i = q - ; i >= ; i --) {
                 if(a[i][j] != '*')
                     printf("%c",a[i][j]);
             }
         }
         printf("\n");
     }
     return ;
 }

J

把单词映射成数字

从起点到终点搜索

 #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 a[][] = {};
 int p[];
 string s[];
 int n;
 int ans[];
 bool idx[] = {false};
 int num = ;
 map<string,int> mapp;

 void dfs(int u,int v) {
     if(u == v)
         return;
     idx[u] = true;
     for(int i = ; i <= num; i ++) {
         if(a[u][i] ==  && idx[i] == false) {
             p[i] =u;
             dfs(i,v);
         }
     }
     idx[u] = false;
 }

 int main() {
     clc(a,);
     mapp.clear();
     n=r();
     // getchar();
     string line,x;
     string s1,s2;
     int k = ;
     int t;
     bool flag = false;
     int u,v;
     for(int i =; i < n; i ++) {
         getline(cin,line);
         stringstream ss(line);
         ss>>x;
         if(mapp[x] == ) {
             mapp[x] = num;
             s[num] = x;
             num ++;
         }
         u = mapp[x];
         while(ss >> x) {
             if(mapp[x] == ) {
                 mapp[x] = num;
                 s[num] = x;
                 num ++;
             }
             v = mapp[x];
             a[u][v] = ;
             a[v][u] = ;
         }
     }
     cin>>s1>>s2;
     if(mapp[s1] == ) {
         mapp[s1] = num;
         num ++;
     }
     u= mapp[s1];
     if(mapp[s2] == ) {
         mapp[s2] = num;
         num ++;
     }
     v = mapp[s2];
     dfs(u,v);
     p[u] = -;
     t = v;
     while(t != -) {
         ans[k ++] = t;
         if(t == ) {
             flag = true;
             break;
         }
         t = p[t];
     }
     if(flag == true) {
         printf("no route found\n");
         return ;
     }
     for(int i = k - ; i >= ; i --) {
         cout<<s[ans[i]]<<" ";
     }
     cout<<s[v]<<endl;

 }

一个人打也挺好玩的