From f89084d0074299c679d10431bda01d819221f7ae Mon Sep 17 00:00:00 2001
From: Wenyuan Huang <157926136+whuang369@users.noreply.github.com>
Date: Thu, 10 Sep 2026 10:47:16 -0700
Subject: [PATCH] Fix #185: align problem 213 checker with the documented
 output format

The statement specifies three integers per operation (l r direction), and
the sample plus every answer file use that format, but chk.cc read only
two: `x=ouf.readInt(); y=x+m-1; z=ouf.readInt();`. It derived the right
endpoint from the segment length and then consumed `r` as the direction,
so the first ordinary operation was misparsed and any statement-compliant
submission was rejected before scoring. The repo's own testdata answers
failed against it.

- chk.cc: read l, r and d as three separate integers, keeping the existing
  interval-length, bounds and direction validation.
- testdata/1.ans: replace an invalid answer (x=3 for n=2, and an operation
  with no direction) with `2 / 1 / 1 2 0`.
- statement.txt: describe x and m on separate lines, matching the sample
  and the answer files, and spell out the l/r/d constraints.
- config.yaml: raise the time limit to the documented 5s.

Verified: all three testdata answers now score (1.0, 0.9577, 0.9952), the
statement's sample scores 1.0, and illegal outputs (wrong interval length,
r > n, direction not in {0,1}) are still rejected.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 algorithmic/problems/213/chk.cc         | 2 +-
 algorithmic/problems/213/config.yaml    | 2 +-
 algorithmic/problems/213/statement.txt  | 6 ++++--
 algorithmic/problems/213/testdata/1.ans | 4 ++--
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/algorithmic/problems/213/chk.cc b/algorithmic/problems/213/chk.cc
index 1b0450d30..fb69361bb 100644
--- a/algorithmic/problems/213/chk.cc
+++ b/algorithmic/problems/213/chk.cc
@@ -59,7 +59,7 @@ int main(int argc,char* argv[])
 		root=merge(root,newnode(b[i]));
 	while(tot--){
 		int u,v,x1,x2,x3,x4,x5;
-		x=ouf.readInt(); y=x+m-1; z=ouf.readInt();
+		x=ouf.readInt(); y=ouf.readInt(); z=ouf.readInt();
 		if(x>y) swap(x,y);
 		if(y-x+1!=m || x<=0 || y>n || (z!=0 && z!=1))
 			quitf(_wa,"Your answer is not legal");
diff --git a/algorithmic/problems/213/config.yaml b/algorithmic/problems/213/config.yaml
index eb050889e..1bdf34e0b 100644
--- a/algorithmic/problems/213/config.yaml
+++ b/algorithmic/problems/213/config.yaml
@@ -5,7 +5,7 @@ type: default
 checker: chk.cc
 
 # Time and memory limits (for submit answer problems, these may not be strictly enforced)
-time: 2s
+time: 5s
 memory: 512m
 
 # The subtasks section
diff --git a/algorithmic/problems/213/statement.txt b/algorithmic/problems/213/statement.txt
index 5d32a1d8d..52acb02ea 100644
--- a/algorithmic/problems/213/statement.txt
+++ b/algorithmic/problems/213/statement.txt
@@ -13,9 +13,11 @@ The first line contains a single integer $n$.
 The second line contains $n$ integers, representing the sequence $a$.
 
 Output Format:
-The first line contains two integers $x$ and $m$, where $m$ represents the number of operations.
+The first line contains a single integer $x$, the chosen segment length.
 
-The next $m$ lines each contain three integers: the first two represent the shift interval, and the last one represents the direction, where $0$ means left and $1$ means right.
+The second line contains a single integer $m$, the number of operations.
+
+The next $m$ lines each contain three integers $l$, $r$, $d$: the first two represent the shift interval (it must satisfy $r - l + 1 = x$, $1 \le l \le r \le n$), and the last one represents the direction, where $0$ means left and $1$ means right.
 
 Example:
 Input:
diff --git a/algorithmic/problems/213/testdata/1.ans b/algorithmic/problems/213/testdata/1.ans
index 62ea367b3..29c7001d2 100644
--- a/algorithmic/problems/213/testdata/1.ans
+++ b/algorithmic/problems/213/testdata/1.ans
@@ -1,3 +1,3 @@
-3
+2
 1
-1 2
+1 2 0