[POJ 1195]Mobile phones

Time Limit: 5000MS Memory Limit: 65536K

Description

Suppose that the fourth generation mobile phone base stations in the Tampere area operate as follows. The area is divided into squares. The squares form an S * S matrix with the rows and columns numbered from 0 to S-1. Each square contains a base station. The number of active mobile phones inside a square can change because a phone is moved from a square to another or a phone is switched on or off. At times, each base station reports the change in the number of active phones to the main base station along with the row and the column of the matrix.

Write a program, which receives these reports and answers queries about the current total number of active mobile phones in any rectangle-shaped area.

Input
The input is read from standard input as integers and the answers to the queries are written to standard output as integers. The input is encoded as follows. Each input comes on a separate line, and consists of one instruction integer and a number of parameter integers according to the following table.

The values will always be in range, so there is no need to check them. In particular, if A is negative, it can be assumed that it will not reduce the square value below zero. The indexing starts at 0, e.g. for a table of size 4 * 4, we have 0 <= X <= 3 and 0 <= Y <= 3.

Table size: 1 * 1 <= S * S <= 1024 * 1024
Cell value V at any time: 0 <= V <= 32767
Update amount: -32768 <= A <= 32767
No of instructions in input: 3 <= U <= 60002
Maximum number of phones in the whole table: M= 2^30

Output
Your program should not answer anything to lines with an instruction other than 2. If the instruction is 2, then your program is expected to answer the query by writing the answer as a single line containing a single integer to standard output.

Sample Input

0 41 1 2 32 0 0 2 2 1 1 1 21 1 2 -12 1 1 2 3 3

Sample Output

34

Source
IOI 2001

简述一下题意，四种操作，0 s 表示建立一个所有格子都是0的、长和宽都是s的矩阵。1 X Y A 给(x , y)这个格子加上A。2 L B R T ，对于 x ∈[L , R], y∈[B,T]，输出所有坐标为(x , y)的格子的值相加的和。

题解：

二维树状数组，也算学到一个新东西了。记住所有坐标都要+1，因为树状数组的格子是从1开始记录的。

#include<iostream>#include<cstdio>#include<cstdlib>#include<cstring>#include<cmath>#include<algorithm>#define ll long long#define LiangJiaJun main#define eps 1e-9using namespace std;int lowbit(int x){return x&(-x);}ll tr[1104][1104];int n,c;void add(int x,int y,ll a){     for(int i=x;i<=n;i+=lowbit(i))         for(int j=y;j<=n;j+=lowbit(j))             tr[i][j]+=a;}ll  ask(int x,int y){    ll ans=0;    for(int i=x;i;i-=lowbit(i))        for(int j=y;j;j-=lowbit(j))ans+=tr[i][j];    return ans;}int LiangJiaJun(){    while(scanf("%d%d",&c,&n)!=EOF){        memset(tr,0,sizeof(tr));        while(1){            scanf("%d",&c);            if(c==3)break;            if(c==1){                int x,y;ll a;                scanf("%d%d%lld",&x,&y,&a);                ++x;++y;add(x,y,a);            }            if(c==2){                int l,b,r,t;                scanf("%d%d%d%d",&l,&b,&r,&t);                ++l;++b;++r;++t;                ll gep=ask(r,t)-ask(l-1,t)-ask(r,b-1)+ask(l-1,b-1);                printf("%lld\n",gep);            }        }    }    return 0;}