HDU 5037 Frog（北京网络赛F题）

HDU Frog

题目链接

思路：贪心搞，记录青蛙当前和上一次的位置，如果遇到一个区间跳不过去，要加石头，就按两步长度为(l + 1)去放会使得步数最大，注意边界条件有可能一步就能跳过去

代码：

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

const int N = 200005;

int t, n, m, l;
int r
;

int solve() {
int ans = 0;
int now = 0;
int pre = -l;
int st = 0;
while (now < m) {
if (now + l < r[st]) {
int tmp = now - pre;
int len = r[st] - now;
int ci = len / (l + 1) - 1;
ans += ci * 2;
now += ci * (l + 1);
pre = now - tmp;
ans++;
pre = now;
now += (1 + l) - tmp;
} else {
while (now + l >= r[st] && st <= n)
st++;
pre = now;
now = r[st - 1];
ans++;
}
}
return ans;
}

int main() {
int cas = 0;
scanf("%d", &t);
while (t--) {
scanf("%d%d%d", &n, &m, &l);
for (int i = 0; i < n; i++)
scanf("%d", &r[i]);
sort(r, r + n);
r
= m;
printf("Case #%d: %d\n", ++cas, solve());
}
return 0;
}