KIDx 的解题报告
http://acm.hdu.edu.cn/listproblem.php?vol=31
4001:直接一个最长递增子序列模板,注意数据范围就可以了
#include <iostream>
#include <algorithm>
using namespace std;
#define L __int64
#define M 1005
struct block{
L a, b, c, d;
}x[M];
L dp[M];
bool cmp (block x, block y)
{
if (x.a == y.a)
{
if (x.b == y.b)
return x.d > y.d;
return x.b < y.b;
}
return x.a < y.a;
}
int main()
{
int n, i, j;
while (scanf ("%d", &n), n)
{
for (i = 0; i < n; i++)
{
scanf ("%I64d%I64d%I64d%I64d", &x[i].a, &x[i].b, &x[i].c, &x[i].d);
if (x[i].a < x[i].b)
x[i].a ^= x[i].b, x[i].b ^= x[i].a, x[i].a ^= x[i].b;
}
sort (x, x+n, cmp);
for (i = 0; i < n; i++)
dp[i] = x[i].c;
for (i = 0; i < n; i++)
{
for (j = i + 1; j < n; j++)
{
if (x[j].d == 0 && x[j].a >= x[i].a && x[j].b >= x[i].b ||
x[j].d == 1 && x[j].a >= x[i].a && x[j].b >= x[i].b &&
x[j].a*x[j].b > x[i].a*x[i].b ||
x[j].d == 2 && x[j].a > x[i].a && x[j].b > x[i].b)
if (dp[j] < dp[i]+x[j].c)
dp[j] = dp[i]+x[j].c;
}
}
printf ("%I64d\n", *max_element (dp, dp+n));
}
return 0;
}
4002:猥琐打表找规律+大数乘法,Java暴力水过
import java.util.*;
import java.io.*;
import java.math.*;
public class Main
{
static public void main(String[] args) throws IOException
{
Scanner cin = new Scanner(new BufferedInputStream(System.in));
BigInteger prime[] = new BigInteger[60], tp, n;
int hash[] = new int[300], k, i, j, num, t;
for (i = 0; i < 300; i++)
hash[i] = 1;
k = 0;
for (i = 2; i < 242; i++)
{
if (hash[i] == 1)
{
prime[k] = BigInteger.valueOf(i);
k++;
for (j = i * 2; j < 242; j += i)
hash[j] = 0;
}
}
for (i = 1; i < k; i++)
prime[i] = prime[i].multiply(prime[i-1]);
t = cin.nextInt();
while (true)
{
if (t == 0)
break;
t--;
n = cin.nextBigInteger();
for (i = 0; i < k; i++)
if (n.compareTo(prime[i]) == -1)
break;
System.out.println(prime[i-1]);
}
}
}
4004:二分枚举答案+暴力检验
#include <iostream>
#include <algorithm>
using namespace std;
#define M 500005
int x[M], v[M];
int main()
{
int L, n, m, i, k, maxs, l, r, mid, num, tp;
while (~scanf ("%d%d%d", &L, &n, &m))
{
x[0] = 0;
for (i = 1; i <= n; i++)
scanf ("%d", x+i);
sort (x, x+n+1);
x[n+1] = L;
k = maxs = 0;
for (i = 1; i < n + 2; i++)
{
v[k++] = x[i] - x[i-1];
if (v[k-1] > maxs)
maxs = v[k-1];
}
l = maxs, r = L;
while (l < r)
{
tp = num = 0;
mid = (l + r) / 2;
for (i = 0; i < k; i++)
{
if (tp + v[i] > mid)
num++, tp = v[i];
else tp += v[i];
}
num++;
if (num <= m)
r = mid;
else l = mid + 1;
}
printf ("%d\n", r);
}
return 0;
}
4006:优先队列暴力水过
#include <iostream>
#include <queue>
using namespace std;
struct Int{
int v;
friend bool operator < (Int a, Int b)
{
return a.v > b.v;
}
};
int main()
{
Int tp;
int n, x, k;
char ch[3];
while (~scanf ("%d%d", &n, &k))
{
priority_queue<Int> q;
while (n--)
{
scanf ("%s", ch);
if (ch[0] == 'Q')
{
while (q.size() > k)
q.pop();
printf ("%d\n", q.top().v);
}
else
{
scanf ("%d", &x);
tp.v = x;
q.push (tp);
}
}
}
return 0;
}
4007:最暴力的解法,相信没有人能够破我记录----史上最慢
先优先sort-x坐标,再枚举2条垂直于x轴的扫描线,再从p数组中筛选出在这2条扫描线中的x个点入tp数组,然后优先sort-y坐标,再枚举2条垂直于y轴的扫描线,再从tp数组中筛选出在这2条扫描线中的tmp个点,就是4条扫描线所围成的正方形里的点的个数
#include <iostream>
#include <algorithm>
using namespace std;
#define M 1005
struct point{
int x, y;
}p[M], tp[M];
bool cmp (point a, point b)
{
if (a.x == b.x)
return a.y < b.y;
return a.x < b.x;
}
bool cmp2 (point a, point b)
{
if (a.y == b.y)
return a.x < b.x;
return a.y < b.y;
}
int main()
{
int n, R, i, j, k, lx, rx, ly, ry, x, maxs, tmp;
while (~scanf ("%d%d", &n, &R))
{
for (i = 0; i < n; i++)
scanf ("%d%d", &p[i].x, &p[i].y);
sort (p, p+n, cmp);
maxs = 0;
for (i = 0; i < n; i++)
{
rx = p[i].x;
lx = rx - R;
x = 0;
for (j = 0; j < n; j++)
{
if (p[j].x > rx)
break;
if (p[j].x >= lx && p[j].x <= rx)
tp[x++] = p[j];
}
sort (tp, tp+x, cmp2);
for (j = 0; j < x; j++)
{
ry = tp[j].y;
ly = ry - R;
tmp = 0;
for (k = 0; k < x; k++)
{
if (tp[k].y > ry)
break;
if (tp[k].y >= ly && tp[k].y <= ry)
tmp++;
}
if (tmp > maxs)
maxs = tmp;
}
}
printf ("%d\n", maxs);
}
return 0;
}
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