Submission #414705

#	Time	Username	Problem	Language	Result	Execution time	Memory
414705		juggernaut	The Xana coup (BOI21_xanadu)	C++17	0 / 100	30 ms	640 KiB

xanadu

#include<bits/stdc++.h>
#define fr first
#define sc second
using namespace std;
void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
typedef long long ll;
#define USING_ORDERED_SET 0
#if USING_ORDERED_SET
#include<bits/extc++.h>
using namespace __gnu_pbds;
template<class T>using ordered_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#endif
template<class T>void umax(T &a,T b){if(a<b)a=b;}
template<class T>void umin(T &a,T b){if(b<a)a=b;}
#ifdef IOI2021SG
    #define printl(args...)printf(args)
#else
    #define printl(args...)((void)0)
#endif
int a[100005];
int main(){
    int n;
    scanf("%d",&n);
    for(int i=1,x;i<n;i++)scanf("%d%d",&x,&x);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    int cnt=0;
    for(int i=2;i<=n;i++){
        if(a[i-1]==0){
            cnt++;
            a[i]^=1;
            a[i+1]^=1;
        }
    }
    if(a[n]==0)puts("impossible");
    else printf("%d",cnt);
}

Compilation message (stderr)

xanadu.cpp: In function 'void usaco(std::string)':
xanadu.cpp:5:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xanadu.cpp:5:66: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                                                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
xanadu.cpp: In function 'int main()':
xanadu.cpp:23:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
xanadu.cpp:24:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |     for(int i=1,x;i<n;i++)scanf("%d%d",&x,&x);
      |                           ~~~~~^~~~~~~~~~~~~~
xanadu.cpp:25:31: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |     for(int i=1;i<=n;i++)scanf("%d",&a[i]);
      |                          ~~~~~^~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3: 0 / 10
• Subtask 4: 0 / 40
• Subtask 5: 0 / 30