hdu 4417 Super Mario(线段树)

/*
首先对问题进行转换，将数据分别用数组做存储，按h大小进行排序，然后从小到大进行询问操作，每次操作之前，首先将第一个数组中h值比这个值小或等于的入队，
于是问题转换为线段树问题
*/
#include <iostream>
#include <cstdio>
#include <cstdlib>

using namespace std;
const int nMax = 100007;
struct Tree
{
int l, r;
int w;
Tree(){}
Tree(int l, int r, int w):l(l), r(r), w(w){}
}tree[4 * nMax];
struct Dat
{
int id, num;
}dat[nMax];
struct Ask
{
int id, l, r, h;
}ask[nMax];
int ans[nMax];

void build(int rt, int l, int r)
{
if(l < r)
{
int mid = (l + r) / 2;
build(rt * 2, l, mid);
build(rt * 2 + 1, mid + 1, r);
}
tree[rt] = Tree(l, r, 0);
}

void update(int rt, int id)
{
if(tree[rt].l <= id && tree[rt].r >= id)
{
tree[rt].w ++;
if(tree[rt].l == tree[rt].r) return;
update(rt * 2, id);
update(rt * 2 + 1, id);
}
}

int sum(int rt, int l, int r)
{
//int ans = 0;
if(r < 0) return 0;
if(tree[rt].l == l && tree[rt].r == r)
return tree[rt].w;
int mid = (tree[rt].l + tree[rt].r) / 2;
if(r <= mid) return sum(rt * 2, l, r);
else if(mid + 1 <= l) return sum(rt * 2 + 1, l, r);
else return sum(rt * 2, l, mid) + sum(rt * 2 + 1, mid + 1, r);
}

int cmp1(const void *a, const void *b)
{
Dat *pa = (Dat *) a;
Dat *pb = (Dat *) b;
return pa ->num - pb ->num;
}

int cmp2(const void *a, const void *b)
{
Ask *pa = (Ask *) a;
Ask *pb = (Ask *) b;
return pa ->h - pb ->h;
}

int main()
{
//cout << "Hello world!" << endl;
//freopen("e://data.in", "r", stdin);
int T;
scanf("%d", &T);
int cas;
int n, m;
for(cas = 1; cas <= T; cas ++)
{
scanf("%d%d", &n, &m);
build(1, 0, n - 1);
int i, j;
for(i = 0; i < n; ++ i)
{
scanf("%d", &dat[i].num);
dat[i].id = i;
}
for(i = 0; i < m; ++ i)
{
scanf("%d%d%d", &ask[i].l, &ask[i].r, &ask[i].h);
ask[i].id = i;
}
qsort(dat, n, sizeof(dat[0]), cmp1);
qsort(ask, m, sizeof(ask[0]), cmp2);
for(i = 0, j = 0; i < m; ++ i)
{
while(j < n && dat[j].num <= ask[i].h)
{
update(1, dat[j].id);
j ++;
}
ans[ask[i].id] = sum(1, 0, ask[i].r) - sum(1, 0, ask[i].l - 1);

}
printf("Case %d:\n", cas);
for(i = 0; i < m; ++ i)
printf("%d\n", ans[i]);
}
return 0;
}