#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define inf __builtin_inf()
constexpr int dy[] = {1, -1, 0, 0};
constexpr int dx[] = {0, 0, 1, -1};
constexpr int N = 4e4 + 5;
char grid[N][N];
bool vis[N][N];
void solve(){
int h, w; cin >> h >> w;
for(int i = 0; i < h; i++){
for(int j = 0; j < w; j++){
cin >> grid[i][j];
}
}
priority_queue<tuple<int, int, int>> q;
q.push({-1, 0, 0});
int mx = 1;
while(sz(q)) {
auto [cost, i, j] = q.top();
q.pop();
if(vis[i][j]) continue;
vis[i][j] = true;
mx = max(mx, -cost);
for(int k = 0; k < 4; k++){
int y = dy[k] + i, x = dx[k] + j;
if(y < 0 || x < 0 || y == h || x == w || vis[y][x]) continue;
q.push({cost - (grid[y][x] != grid[i][j]), y, x});
}
}
cout << mx;
}
int main(){
ios_base::sync_with_stdio(false), cin.tie(NULL);
// int t; cin >> t; while(t--)
solve(), cout << '\n';
return 0;
}
Compilation message (stderr)
/tmp/ccwXzOeQ.o: in function `solve()':
tracks.cpp:(.text+0xf): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cin' defined in .bss._ZSt3cin section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
tracks.cpp:(.text+0x617): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cout' defined in .bss._ZSt4cout section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
/tmp/ccwXzOeQ.o: in function `main':
tracks.cpp:(.text.startup+0x22): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cin' defined in .bss._ZSt3cin section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
tracks.cpp:(.text.startup+0x3c): relocation truncated to fit: R_X86_64_PC32 against symbol `std::cout' defined in .bss._ZSt4cout section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
/tmp/ccwXzOeQ.o: in function `_GLOBAL__sub_I_grid':
tracks.cpp:(.text.startup+0x78): relocation truncated to fit: R_X86_64_PC32 against `.bss'
/usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(vterminate.o): in function `__gnu_cxx::__verbose_terminate_handler()':
(.text._ZN9__gnu_cxx27__verbose_terminate_handlerEv+0x1e): relocation truncated to fit: R_X86_64_PC32 against `.bss._ZZN9__gnu_cxx27__verbose_terminate_handlerEvE11terminating'
(.text._ZN9__gnu_cxx27__verbose_terminate_handlerEv+0x2b): relocation truncated to fit: R_X86_64_PC32 against `.bss._ZZN9__gnu_cxx27__verbose_terminate_handlerEvE11terminating'
/usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(ios_init.o): in function `std::ios_base::Init::Init()':
(.text._ZNSt8ios_base4InitC2Ev+0x1c): failed to convert GOTPCREL relocation against '_ZNSt8ios_base4Init11_S_refcountE'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x60): relocation truncated to fit: R_X86_64_PC32 against symbol `__gnu_internal::buf_cout_sync' defined in .bss._ZN14__gnu_internal13buf_cout_syncE section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
(.text._ZNSt8ios_base4InitC2Ev+0x67): relocation truncated to fit: R_X86_64_PC32 against symbol `__gnu_internal::buf_cout_sync' defined in .bss._ZN14__gnu_internal13buf_cout_syncE section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
(.text._ZNSt8ios_base4InitC2Ev+0x72): relocation truncated to fit: R_X86_64_PC32 against symbol `__gnu_internal::buf_cout_sync' defined in .bss._ZN14__gnu_internal13buf_cout_syncE section in /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.a(globals_io.o)
(.text._ZNSt8ios_base4InitC2Ev+0x87): additional relocation overflows omitted from the output
(.text._ZNSt8ios_base4InitC2Ev+0x1c6): failed to convert GOTPCREL relocation against '_ZSt4cout'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x260): failed to convert GOTPCREL relocation against '_ZSt3cin'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x2e2): failed to convert GOTPCREL relocation against '_ZSt4cerr'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x353): failed to convert GOTPCREL relocation against '_ZSt4clog'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x541): failed to convert GOTPCREL relocation against '_ZSt5wcout'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x5e5): failed to convert GOTPCREL relocation against '_ZSt4wcin'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x670): failed to convert GOTPCREL relocation against '_ZSt5wcerr'; relink with --no-relax
(.text._ZNSt8ios_base4InitC2Ev+0x6e9): failed to convert GOTPCREL relocation against '_ZSt5wclog'; relink with --no-relax
/usr/bin/ld: final link failed
collect2: error: ld returned 1 exit status
