Uva 12503 - Robot Instructions

你为何这么叼！

Robot Instructions 

Time limit: 1.000 seconds 

 

You have a robot standing on the origin of x axis. The robot will be given some instructions. Your task is to predict its position after executing all the instructions.

• LEFT: move one unit left (decrease p by 1, where p is the position of the robot before moving)
• RIGHT: move one unit right (increase p by 1)
• SAME AS i: perform the same action as in the i-th instruction. It is guaranteed that i is a positive integer not greater than the number of instructions before this.

Input 

The first line contains the number of test cases T (T100). Each test case begins with an integer n ( 1n100), the number of instructions. Each of the following n lines contains an instruction.

Output 

For each test case, print the final position of the robot. Note that after processing each test case, the robot should be reset to the origin.

Sample Input 

2
3
LEFT
RIGHT
SAME AS 2
5
LEFT
SAME AS 1
SAME AS 2
SAME AS 1
SAME AS 4

Sample Output 

1
-5

 

---

Problemsetter: Rujia Liu, Special Thanks: Feng Chen, Md. Mahbubul Hasan

 

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define maxn 111
int n,m,k;
int a[maxn];
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        scanf("%d",&n);
        int x=0,i=1;
        while(n--){
            char op[31];
            scanf("%s",op);
            if(op[0]=='L'){x--;a[i++]=-1;continue;}
            if(op[0]=='R'){x++;a[i++]=1;continue;}
            scanf("%s%d",op,&k);x+=a[k];a[i++]=a[k];
        }
        printf("%d\n",x);
    }
    return 0;
}