Submission #68390

#	Time	Username	Problem	Language	Result	Execution time	Memory
68390		nvmdava	Aliens (IOI07_aliens)	C++17	80 / 100	1081 ms	548 KiB

aliens

#include <bits/stdc++.h>
using namespace std;

int n;
char s[10];

bool ask(int x, int y){
	if(x > n || x < 1 || y > n || y < 1){
		return 0;
	}
	printf("examine %d %d\n", x, y);
	fflush(stdout);
	scanf("%s", &s);
	return (s[0] == 't');
}

int x, y, m;

int main(){
	scanf("%d %d %d",&n,&x,&y);
	if(n > (1 << 29)){
		cout<<"A";
	}
	int left, right, up, down;
	
	int l = 0, r = x;
	while(l + 1 != r){
		int m = (l + r) / 2;
		if(ask(m, y)){
			r = m;
		} else {
			l = m;
		}
	}
	left = l;
	
	l = x, r = n + 1;
	while(l + 1 != r){
		int m = (l + r) / 2;
		if(ask(m, y)){
			l = m;
		} else {
			r = m;
		}
	}
	right = l;
	
	l = 0, r = y;
	while(l + 1 != r){
		int m = (l + r) / 2;
		if(ask(x, m)){
			r = m;
		} else {
			l = m;
		}
	}
	up = l;
	
	l = y, r = n + 1;
	while(l + 1 != r){
		int m = (l + r) / 2;
		if(ask(x, m)){
			l = m;
		} else {
			r = m;
		}
	}
	down = l;
	
	m = __gcd(right - left, down - up);
	right = left + m;
	down = up + m;
	x = (right + left) / 2 + 1;
	y = (down + up) / 2 + 1;
	if(m % 3 == 0){
		if(ask(x, y + m / 3) == 0){
			m /= 3;
		}
	}
	if(m % 5 == 0){
		if(ask(x + m / 5, y) == 0){	
			m /= 5;
		}
	}
	right = left + m;
	down = up + m;
	x = (right + left) / 2 + 1;
	y = (down + up) / 2 + 1;
	
	while(ask(x - m, y - m) ){
		x -= m;
		y -= m;
	}
	while(ask(x - 2 * m, y) ){
		x -= 2 * m;
	}
	while(ask(x, y - 2 * m) ){
		y -= m * 2;
	}
	
	printf("solution %d %d\n", x + 2 * m, y + 2 * m);
}

Compilation message (stderr)

aliens.cpp: In function 'bool ask(int, int)':
aliens.cpp:13:16: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[10]' [-Wformat=]
  scanf("%s", &s);
              ~~^
aliens.cpp:13:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", &s);
  ~~~~~^~~~~~~~~~
aliens.cpp: In function 'int main()':
aliens.cpp:20:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  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: 0 / 10
• Subtask 10: 0 / 10