Submission #827757

#	Time	Username	Problem	Language	Result	Execution time	Memory
827757		nnin	Aliens (IOI07_aliens)	C++14	100 / 100	2 ms	296 KiB

aliens

#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define f first
#define s second
using namespace std;

int n, x, y, m;

bool interact(int xx, int yy) {
    if(xx==x && yy==y) return 1;
    printf("examine %lld %lld\n", xx, yy);
    string s;
    cin>>s;
    return s[0]=='t';
}

int32_t main() {
    scanf("%d %d %d", &n, &x, &y);
    int l, r, two;

    two = 1;
    while(x+two<=n && interact(x+two, y)) two *= 2;
    l = x+(two/2);
    r = min(x+two, n);
    while(l<r) {
        int mid = (l+r+1)/2;
        if(interact(mid, y)) l = mid;
        else r = mid-1;
    }
    int right = l;

    two = 1;
    while(x-two>=1 && interact(x-two, y)) two *= 2;
    l = max(x-two, (int)1);
    r = x-(two/2);
    while(l<r) {
        int mid = (l+r)/2;
        if(interact(mid, y)) r = mid;
        else l = mid+1;
    }
    int left = l;

    two = 1;
    while(y+two<=n && interact(x, y+two)) two *= 2;
    l = y+(two/2);
    r = min(y+two, n);
    while(l<r) {
        int mid = (l+r+1)/2;
        if(interact(x, mid)) l = mid;
        else r = mid-1;
    }
    int top = l;

    two = 1;
    while(y-two>=1 && interact(x, y-two)) two *= 2;
    l = max(y-two, (int)1);
    r = y-(two/2);
    while(l<r) {
        int mid = (l+r)/2;
        if(interact(x, mid)) r = mid;
        else l = mid+1;
    }
    int bottom = l;

    m = right+1-left;
    int xc = (left+right)/2;
    int yc = (top+bottom)/2;

    while(xc-m>=1 && yc-m>=1 && interact(xc-m, yc-m)) {
        xc -= m;
        yc -= m;
    }
    while(xc-(2*m)>=1 && interact(xc-(2*m), yc)) xc -= 2*m;
    while(yc-(2*m)>=1 && interact(xc, yc-(2*m))) yc -= 2*m;
    xc += 2*m;
    yc += 2*m;

    printf("solution %lld %lld", xc, yc);
}

Compilation message (stderr)

aliens.cpp: In function 'int32_t main()':
aliens.cpp:19:13: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
   19 |     scanf("%d %d %d", &n, &x, &y);
      |            ~^         ~~
      |             |         |
      |             int*      long long int*
      |            %lld
aliens.cpp:19:16: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'long long int*' [-Wformat=]
   19 |     scanf("%d %d %d", &n, &x, &y);
      |               ~^          ~~
      |                |          |
      |                int*       long long int*
      |               %lld
aliens.cpp:19:19: warning: format '%d' expects argument of type 'int*', but argument 4 has type 'long long int*' [-Wformat=]
   19 |     scanf("%d %d %d", &n, &x, &y);
      |                  ~^           ~~
      |                   |           |
      |                   int*        long long int*
      |                  %lld
aliens.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |     scanf("%d %d %d", &n, &x, &y);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10