race.cpp: In function 'void init(long long int, long long int)':
race.cpp:28:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
28 | for(auto [v,w]:g[u]){
| ^
race.cpp: In function 'void dfs(long long int, long long int)':
race.cpp:47:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
47 | for(auto [v,w]:g[u]){
| ^
race.cpp:51:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
51 | for(auto [v,w]:g[u]){
| ^
race.cpp:61:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
61 | for(auto [v,w]:g[u]){
| ^
race.cpp: In function 'int main()':
race.cpp:91:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
91 | freopen("test.inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
race.cpp:92:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
92 | freopen("test.out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccUKaSuG.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccSOTdiF.o:grader.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccSOTdiF.o: in function `main':
grader.cpp:(.text.startup+0x28): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status