Submission #357716

#	Time	Username	Problem	Language	Result	Execution time	Memory
357716		mjhmjh1104	Colors (BOI20_colors)	C++14	0 / 100	1 ms	384 KiB

Colors

#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

vector<long long> v;

long long n;
int t;

int main() {
    scanf("%lld", &n);
    long long curr = 1;
    long long l = n / 2, r = n - 1;
    while (l < r) {
        v.push_back(l);
        l = (l + r) / 2 + 1;
    }
    v.push_back(l);
    reverse(v.begin(), v.end());
    for (auto &i: v) {
        if (curr + i <= n) curr += i;
        else curr -= i;
    }
    printf("? %lld\n", curr);
    fflush(stdout);
    scanf("%*d");
    l = 0, r = n - 1;
    while (l < r) {
        long long m = (l + r) / 2;
        if (curr + m <= n) curr += m;
        else curr -= m;
        printf("? %lld\n", curr);
        fflush(stdout);
        scanf("%d", &t);
        if (t) r = m;
        else l = m + 1;
    }
    if (l == n - 1) {
        printf("? %lld\n", n);
        fflush(stdout);
        scanf("%d", &t);
        if (t) printf("= %lld\n", n - 1);
        else printf("= %lld\n", n);
    } else printf("= %lld\n", l);
    fflush(stdout);
}

Compilation message (stderr)

Colors.cpp: In function 'int main()':
Colors.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 |     scanf("%lld", &n);
      |     ~~~~~^~~~~~~~~~~~
Colors.cpp:27:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   27 |     scanf("%*d");
      |     ~~~~~^~~~~~~
Colors.cpp:35:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |         scanf("%d", &t);
      |         ~~~~~^~~~~~~~~~
Colors.cpp:42:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   42 |         scanf("%d", &t);
      |         ~~~~~^~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 13
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 33