Submission #1972134

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Source Code Expand

#include "bits/stdc++.h"

using namespace std;
using ll = long long;
using IP = pair<int, int>;

const ll linf = 1LL << 62;
const int inf = 99999999;
const int dx[4] = { 1,0,-1,0 };
const int sy[4] = { 0,1,0,-1 };
const ll atcoder = 1e9 + 7;

#define Endl endl
#define mp make_pair
#define all(v) v.begin(),v.end()
#define pb push_back
#define pr(x) cout << x << endl
#define chmax(x,y) x = max(x,y)
#define chmin(x,y) x = min(x,y)
#define rep(i,n) for(int i= 0;i<n;i++)

ll gcd(ll a, ll b) {//最大公約数
	if (a%b == 0)return b;
	else gcd(b, a%b);
}

ll lcm(ll a, ll b) {//最小公倍数
	return (a / gcd(a, b))*b;
}

int c[1000001] = { 0 };

int main(){

	int n;
	cin >> n;

	for (int i = 0; i<n; i++) {
		ll a, b;
		cin >> a >> b;
		c[a] ++;
		c[b + 1] --;
	}

	for (int i = 1; i <= 1000001; i++) {
		c[i] += c[i - 1];
	}

	int ans = -inf;
	for (int i = 0; i <= 1000001; i++) {
		chmax(ans, c[i]);
	}

	pr(ans);

	//system("pause");
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:46:19: warning: iteration 1000000u invokes undefined behavior [-Waggressive-loop-optimizations]
   c[i] += c[i - 1];
                   ^
./Main.cpp:45:20: note: containing loop
  for (int i = 1; i <= 1000001; i++) {
                    ^

Judge Result