题目： CF1690E Price Maximization
代码：

Probably, the solution is executed with error 'out of bounds' on the line 38
#include <bits/stdc++.h>
using namespace std;
#define ll long long
ll T, n, k, a[200010];
vector<ll> f[1010];
int main(){
	cin >> T;
	while(T--){
		scanf("%lld %lld", &n, &k);
		for(ll i = 0; i < k; i++) f[i].clear();
		for(ll i = 1; i <= n; i++){
			scanf("%lld", &a[i]); f[a[i] % k].push_back(a[i]);
		}
		ll ans = 0;
		for(ll i = 0; i < k; i++){
			if(!f[i].size()) continue;
			if(i == 0){
				ll t = f[i].size();
				for(ll j = 1; j <= t / 2; j++){
					ll t1 = f[i][f[i].size() - 1], t2 = f[i][f[i].size() - 2];
					ans += (t1 + t2) / k;
					f[i].pop_back(); f[i].pop_back();
				}
			}else{
				ll t = min(f[i].size(), f[k - i].size());
				for(ll j = 1; j <= t; j++){
					ll t1 = f[i][f[i].size() - 1], t2 = f[k - i][f[k - i].size() - 1];
					ans += (t1 + t2) / k;
					f[i].pop_back(); f[k - i].pop_back();
				}
			}
		}
		ll last = -1;
		for(ll i = 0; i < k; i++)
			if(f[i].size()){
				ll t = f[i].size();
				for(ll tmp = 0; tmp < t; tmp++){
 					ll j = f[i][tmp]; //这是报错的地方（行）
					if(last == -1) last = j;
					else{
						ans += (last + j) / k; last = -1;
					}
					if(f[i].size() > 1) f[i].pop_back();
				}
			}
		printf("%lld\n", ans);
	}
	return 0;
}

CF 报错：

Diagnostics detected issues [cpp.clang++-diagnose]: =================================================================
==4560==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x13200198 at pc 0x00ab434e bp 0x1124ec14 sp 0x1124ec10
READ of size 8 at 0x13200198 thread T0
==4560==WARNING: Failed to use and restart external symbolizer!
    #0 0xab434d in main K:\codeforces71\f1c52866cb1978b34ee994e89371cee3\compile-06b338c55c3ccce0450200b1db48e07b\p71.cpp:38
    #1 0xb2d6f1 in __scrt_common_main_seh f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283
    #2 0x769467f8 in BaseThreadInitThunk+0x18 (C:\Windows\System32\KERNEL32.DLL+0x6b8167f8)
    #3 0x778a7f4c in RtlGetFullPathName_UEx+0xac (C:\Windows\SYSTEM32\ntdll.dll+0x4b2e7f4c)
    #4 0x778a7f1a in RtlGetFullPathName_UEx+0x7a (C:\Windows\SYSTEM32\ntdll.dll+0x4b2e7f1a)

0x13200198 is located 0 bytes to the right of 8-byte region [0x13200190,0x13200198)
allocated by thread T0 here:
    #0 0xb2bc77 in operator new C:\src\llvm_package_1201-final\llvm-project\compiler-rt\lib\asan\asan_new_delete.cpp:99
    #1 0xad6aad in std::_Default_allocate_traits::_Allocate C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.14.26428\include\xmemory0:52
    #2 0xad68e7 in std::_Allocate<8,std::_Default_allocate_traits,0> C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.14.26428\include\xmemory0:201
    #3 0xaefafc in std::allocator<long long>::allocate C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.14.26428\include\xmemory0:1036
    #4 0xaeeac4 in std::vector<long long,std::allocator<long long> >::_Emplace_reallocate<const long long &> C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.14.26428\include\vector:1005
    #5 0xaee16d in std::vector<long long,std::allocator<long long> >::emplace_back<const long long &> C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.14.26428\include\vector:971
    #6 0xab613b in std::vector<long long,std::allocator<long long> >::push_back C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Tools\MSVC\14.14.26428\include\vector:981
    #7 0xab209d in main K:\codeforces71\f1c52866cb1978b34ee994e89371cee3\compile-06b338c55c3ccce0450200b1db48e07b\p71.cpp:12
    #8 0xb2d6f1 in __scrt_common_main_seh f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283
    #9 0x769467f8 in BaseThreadInitThunk+0x18 (C:\Windows\System32\KERNEL32.DLL+0x6b8167f8)
    #10 0x778a7f4c in RtlGetFullPathName_UEx+0xac (C:\Windows\SYSTEM32\ntdll.dll+0x4b2e7f4c)
    #11 0x778a7f1a in RtlGetFullPathName_UEx+0x7a (C:\Windows\SYSTEM32\ntdll.dll+0x4b2e7f1a)

SUMMARY: AddressSanitizer: heap-buffer-overflow K:\codeforces71\f1c52866cb1978b34ee994e89371cee3\compile-06b338c55c3ccce0450200b1db48e07b\p71.cpp:38 in main
Shadow bytes around the buggy address:
  0x3263ffe0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x3263fff0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x32640000: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x32640010: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x32640020: fa fa fa fa fa fa fa fa fa fa 00 fa fa fa 00 fa
=>0x32640030: fa fa 00[fa]fa fa fd fd fa fa 00 00 fa fa fd fd
  0x32640040: fa fa fd fa fa fa fd fa fa fa fd fa fa fa 00 fa
  0x32640050: fa fa 06 fa fa fa fd fa fa fa 05 fa fa fa 06 fa
  0x32640060: fa fa 01 fa fa fa fd fa fa fa fd fa fa fa fd fa
  0x32640070: fa fa fd fa fa fa fd fa fa fa 00 fa fa fa fd fa
  0x32640080: fa fa fd fa fa fa fd fa fa fa fd fa fa fa fd fa
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
  Shadow gap:              cc
==4560==ABORTING