C++-POJ1009-Edge Detection(未完成,有C++代码)

RLE编码，还不会，先搬运一下大佬的代码，理解之后再用Java自己实现

#include <map>
#include <vector>
#include <cstdlib>
#include <iostream>
using namespace std;
static int around[8][2]= {{-1,-1},{-1,0},{-1,1},{0,-1},{0,1},{1,-1},{1,0},{1,1}};
map<int,int>::iterator a_It,b_It;
map<int,int> a,b;
vector<int> s;
int getValue(int index) {
    int value=0;
    for(a_It = a.begin(); a_It != a.end(); a_It++) {
        if(index<a_It->first) break;
        value=a_It->second;
    }
    return value;
}
int getMax(int index,int width,int count) {
    int center=getValue(index);
    int h=index/width;
    int max=0;
    for(int i=0; i<8; i++) {
        int sub=index+around[i][0]*width+around[i][1];
        if(h+around[i][0]==sub/width && sub>=0 && sub<count) {
            int a=getValue(sub);
            max=abs(center-a)>max?abs(center-a):max;
        }
    }
    return max;
}
void process(int width,int count) {
    for(int i=0; i < s.size(); i++) {
        int index=s.at(i);
        b.insert(pair<int,int>(index,getMax(index,width,count)));
    }
}
int main() {
    int width;
    while(cin>>width && cout<<width<<endl && width) {
        a.clear(),b.clear(),s.clear();
        int v,l,count=0;
        while(cin>>v>>l && l) { //v有可能为0
            a.insert(pair<int,int>(count,v));
            count+=l;
        }
        for(a_It = a.begin(); a_It != a.end(); a_It++) {
            for(int i=-1; i<2; i++) {
                for(int j=-1; j<2; j++) {
                    int index=a_It->first+i*width+j;
                    if(index>=0 && index <count)
                        s.push_back(index);
                }
            }
        }
        s.push_back(width);
        s.push_back(count-width);
        process(width,count);

        b_It = b.begin();
        int s=b_It->first;
        int val=b_It->second;
        b_It++;
        for(; b_It != b.end(); b_It++) {
            if(b_It->second != val) {
                cout<<val<<" "<<b_It->first-s<<endl;
                s=b_It->first;
                val=b_It->second;
            }
        }
        cout<<val<<" "<<count-s<<endl;
        cout<<"0 0"<<endl;
    }
    return 0;
}