CSU 1510 Happy Robot

1510: Happy Robot

Time Limit: 1 Sec  Memory Limit: 128 MB
Submit: 19  Solved: 7

Description

Input

There will be at most 1000 test cases. Each case contains a command sequence with no more than 1000 characters.

Output

For each test case, print the case number, followed by minimal/maximal possible x (in this order), then the minimal/maximal possible y.

Sample Input

F?F
L??
LFFFRF

Sample Output

Case 1: 1 3 -1 1
Case 2: -1 1 0 2
Case 3: 1 1 3 3

HINT

 

Source

湖南省第十届大学生计算机程序设计竞赛

解题：dp啦，现场居然没做出来。。。笨得还可以。。

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <cmath>
 #include <algorithm>
 #include <climits>
 #include <vector>
 #include <queue>
 #include <cstdlib>
 #include <string>
 #include <set>
 #include <stack>
 #define LL long long
 #define pii pair<int,int>
 #define INF 0x3f3f3f3f
 using namespace std;
 const int maxn = ;
 char cmd[maxn];
 int dp[][];
 const int dir[][] = {,,,-,-,,,};//右 下 左 上
 int mymax(int a,int b){
     return max(a,b);
 }
 int mymin(int a,int b){
     return min(a,b);
 }
 int go(int (*op)(int,int),bool flag,int x,int y){
     int cur = ;
         dp[][] = ;
         for(int i = ; i < ; ++i)
             if(flag) dp[][i] = -INF;
             else dp[][i] = INF;
         for(int i = ; cmd[i]; ++i) {
             for(int k = ; k < ; ++k) dp[cur^][k] = flag?-INF:INF;
             if(cmd[i] == 'F' || cmd[i] == '?') {
                 dp[cur^][] = op(dp[cur^][],dp[cur][]+x);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]-y);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]-x);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]+y);
             }
             if(cmd[i] == 'L' || cmd[i] == '?') {
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
             }
             if(cmd[i] == 'R' || cmd[i] == '?') {
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
                 dp[cur^][] = op(dp[cur^][],dp[cur][]);
             }
             cur ^= ;
         }
         int ans = flag?-INF:INF;
         for(int i = ; i < ; ++i)
             ans = op(dp[cur][i],ans);
         return ans;
 }
 int main() {
     int cs = ;
     while(~scanf("%s",cmd)) {
         int max_x = go(mymax,true,,);
         int min_x = go(mymin,false,,);
         int max_y = go(mymax,true,,);
         int min_y = go(mymin,false,,);
         printf("Case %d: %d %d %d %d\n",cs++,min_x,max_x,min_y,max_y);
     }
     return ;
 }