Codevs 4159 Hzwer's mystery series

Title Description Description

Hzwer found a harmless series of mysteries ...

Now Hzwer want to do some work on this sequence, please answer the question of hzwer.

Operation One: Query the size of number I

Operation Two: Change the size of number I to X

Action Three: Reverses the entire sequence. That is, I put the number of the first n-i+1.

Enter a description Input Description

Input data The first row of two number n,m, indicating the sequence length and operand.

The second row n number, which represents the initial value of n elements.

The following m lines, beginning with a number OPR per line, indicate the type of operation.

Opr=1, followed by a number I, which indicates the size of the query number I.

Opr=2 is followed by two number i,x, which indicates that the number of I is changed to X.

A opr=3 that represents the sequence reversal.

Output description Output Description

For each query, output the answer.

Sample input Sample Input

4 6

1 3 2 4

1 3

2 2 6

3

2 1 3

1 3

1 1

Sample output Sample Output

2

6

3

Data range and Tips Data Size & Hint

For 20% data, 1<=n,m<=10.

For 40% data, 1<=n,m<=100.

For 60% data, 1<=n,m<=1000.

For 100% data, 1<=n,m<=100000,1<=a[i]<=100000.

Ideas:

Simulates whether the record is reversed.

Code:

#include <cstdio>using namespacestd;intn,m,a[100001];BOOLFlag;intMain () {inti,j,x,y,z; scanf ("%d%d",&n,&m);  for(i=1; i<=n;i++) scanf ("%d",&A[i]);  for(i=1; i<=m;i++) {scanf ("%d",&x); if(x==1) {scanf ("%d",&y); if(!flag) printf ("%d\n", A[y]); Elseprintf ("%d\n", a[n-y+1]); }        Else          if(x==2) {scanf ("%d%d",&y,&z); if(!flag) A[y]=Z; ElseA[n-y+1]=Z; }          ElseFlag=!Flag; }    return 0;}

Codevs 4159 Hzwer's mystery series