HDU 1541 Stars (tree array), hdu1541

HDU 1541 Stars (tree array), hdu1541
Problem descriptionastpolicmers often examine star maps where stars are represented by points on a plane and each star has Cartesian coordinates. let the level of a star be an amount of the stars that are not higher and not to the right of the given star. astpolicmers want to know the distribution of the levels of the stars.



For example, look at the map shown on the figure above. level of the star number 5 is equal to 3 (it's formed by three stars with a numbers 1, 2 and 4 ). and the levels of the stars numbered by 2 and 4 are 1. at this map there are only one star of the level 0, two stars of the level 1, one star of the level 2, and one star of the level 3.

You are to write a program that will count the amounts of the stars of each level on a given map.

InputThe first line of the input file contains a number of stars N (1 <=n <= 15000 ). the following N lines describe coordinates of stars (two integers X and Y per line separated by a space, 0 <= X, Y <= 32000 ). there can be only one star at one point of the plane. stars are listed in ascending order of Y coordinate. stars with equal Y coordinates are listed in ascending order of X coordinate.

OutputThe output shoshould contain N lines, one number per line. the first line contains amount of stars of the level 0, the second does amount of stars of the level 1 and so on, the last line contains amount of stars of the level N-1.

Sample Input

51 15 17 13 35 5

 

Sample Output

12110

 

Directly count the number not greater than the current number, and then hash the record.

#include <iostream>#include <cstring>#include <cstdio>#include <cmath>#include <set>#include <stack>#include <cctype>#include <algorithm>#define lson o<<1, l, m#define rson o<<1|1, m+1, rusing namespace std;typedef long long LL;const int mod = 99999997;const int MAX = 0x3f3f3f3f;const int maxn = 15050;const int N = 32005;int n, a, b;int c[N], ans[maxn];int main(){    while(~scanf("%d", &n)) {        memset(c, 0, sizeof(c));        memset(ans, 0, sizeof(ans));        int k = 0;        for(int i = 1; i <= n; i++) {            scanf("%d%d", &a, &b); a++;            int sum = 0;            for(int j = a; j > 0; j -= j&(-j)) sum += c[j];            for(int j = a; j <= N; j += j&(-j)) c[j]++;            ans[sum]++;        }        for(int i = 0; i < n; i++) printf("%d\n", ans[i]);    }    return 0;}

Zookeeper
HDU 3743 is just starting to look at the tree array. After reading it, you can only read some of the simplest questions.

Tree arrays are not mentioned here. They are learned by yourself. We recommend that you first make a water question. There are more than 10 typical questions in Baidu Library. For each question, it is required when you do not ask, but you only need to briefly ask your thoughts. If you ask every step in detail, the game will not be exploitable!

Tree array, HDU1166, enemy soldiers, battle. I don't know whether it's an endless loop or something is hard to write.

50000
Are you using an array? Do you need to use a number array so small?