Submission #107755

#	Time	Username	Problem	Language	Result	Execution time	Memory
107755		Just_Solve_The_Problem	Boat (APIO16_boat)	C++11	9 / 100	3 ms	412 KiB

boat

#include <bits/stdc++.h>

#define ll long long

using namespace std;

const int N = (int)507;
const int mod = (int)1e9 + 7; 

int add(int a, int b) {
	return (a + b) % mod;
}

int mul(int a, int b) {
	return (a * 1LL * b) % mod;
}

int n;
int a[N], b[N];

struct fen {
	int tree[N];
	fen() {
		memset(tree, 0, sizeof tree);
	}
	void upd(int pos, int val) {
		while (pos < N) {
			tree[pos] = add(tree[pos], val);
			pos = pos | pos + 1;
		}
	}
	int get(int r) {
		int res = 0;
		while (r >= 0) {
			res = add(res, tree[r]);
			r = (r & r + 1) - 1;
		}
		return res;
	}
};
fen tr;

main() {
	scanf("%d", &n);
	vector < int > vec;
	vec.push_back(-1e9);
	for (int i = 1; i <= n; i++) {
		scanf("%d %d", &a[i], &b[i]);
		vec.push_back(a[i]);
	}
	sort(vec.begin(), vec.end());
	for (int i = 1; i <= n; i++) {
		a[i] = lower_bound(vec.begin(), vec.end(), a[i]) - vec.begin();
	}
	tr.upd(0, 1);
	for (int i = 1; i <= n; i++) {
		tr.upd(a[i], tr.get(a[i] - 1));
	}
	cout << add(tr.get(N - 1), mod - 1);
}

Compilation message (stderr)

boat.cpp: In member function 'void fen::upd(int, int)':
boat.cpp:29:20: warning: suggest parentheses around arithmetic in operand of '|' [-Wparentheses]
    pos = pos | pos + 1;
                ~~~~^~~
boat.cpp: In member function 'int fen::get(int)':
boat.cpp:36:15: warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]
    r = (r & r + 1) - 1;
             ~~^~~
boat.cpp: At global scope:
boat.cpp:43:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^
boat.cpp: In function 'int main()':
boat.cpp:44:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
boat.cpp:48:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &a[i], &b[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42