【BZOJ1664】[Usaco2006 Open]County Fair Events 參加節日慶祝【線段覆蓋】【貪心】

【題目鏈接】

怎麼選到了這麼水的題...

/* Telekinetic Forest Guard */
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

const int maxn = 10005;

int n;

struct _data {
	int l, r;

	bool operator < (const _data &x) const {
		return r != x.r ? r < x.r : l < x.l;
	}
} line[maxn];

inline int iread() {
	int f = 1, x = 0; char ch = getchar();
	for(; ch < '0' || ch > '9'; ch = getchar()) f = ch == '-' ? -1 : 1;
	for(; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
	return f * x;
}

int main() {
	n = iread();
	for(int i = 1; i <= n; i++) line[i].l = iread(), line[i].r = line[i].l + iread();
	sort(line + 1, line + 1 + n);

	int ans = 0;
	for(int i = 1, now = 0; i <= n; i++)
		if(now <= line[i].l) ans++, now = line[i].r;
	printf("%d\n", ans);
	return 0;
}