E - Down or Right Codeforces Round #504 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final)
http://codeforces.com/contest/1023/problem/E
交互题
1 #include <cstdio> 2 #include <cstdlib> 3 #include <cmath> 4 #include <cstring> 5 #include <time.h> 6 #include <string> 7 #include <set> 8 #include <map> 9 #include <list> 10 #include <stack> 11 #include <queue> 12 #include <vector> 13 #include <bitset> 14 #include <ext/rope> 15 #include <algorithm> 16 #include <iostream> 17 using namespace std; 18 #define ll long long 19 #define minv 1e-6 20 #define inf 1e9 21 #define pi 3.1415926536 22 #define E 2.7182818284 23 const ll mod=1e9+7;//998244353 24 const int maxn=1e5+10; 25 26 char S[10]; 27 int s[1000],t[1000]; 28 29 int main() 30 { 31 int n,x,y,tot,xx,yy,i; 32 scanf("%d",&n); 33 x=n,y=n,tot=2*n; 34 while (x-1+y-1>=n) 35 { 36 tot--; 37 s[tot]=x; 38 t[tot]=y; 39 40 printf("? %d %d %d %d\n",1,1,x-1,y); 41 fflush(stdout); 42 scanf("%s",S); 43 if (strcmp(S,"YES")==0) 44 x--; 45 else 46 y--; 47 } 48 tot--; 49 s[tot]=x; 50 t[tot]=y; 51 52 xx=x,yy=y; 53 54 tot=0; 55 x=1,y=1; 56 while (x!=xx || y!=yy) 57 { 58 tot++; 59 s[tot]=x; 60 t[tot]=y; 61 62 printf("? %d %d %d %d\n",x,y+1,n,n); 63 fflush(stdout); 64 scanf("%s",S); 65 if (strcmp(S,"YES")==0) 66 y++; 67 else 68 x++; 69 } 70 71 printf("! "); 72 for (i=2;i<=2*n-1;i++) 73 if (s[i]==s[i-1]) 74 printf("R"); 75 else 76 printf("D"); 77 return 0; 78 }
