原来自己写了一个版本，虽然AC了但是过程很复杂，最后看了这位大神（http://blog.csdn.net/lyy289065406/article/details/6648671）的方法以后，又用跳跃式编程写了一个版本，果然简单多了。

//problem 1009
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;

struct rle
{
	int value;
	int length;
	int index;
};

struct edge
{
	int value;
	int pos;
	bool operator<(const edge& other)
	{
		return pos < other.pos;
	}
};

int height, width, n;

vector<rle> v_in;
vector<edge> v_edge;

int get_value(int k, int i, int j)
{
	int index = i*width + j;
	while(index < v_in[k].index) --k;
	while(index >= v_in[k].index + v_in[k].length) ++k;
	return v_in[k].value;
}

int get_edge(int k, int row, int col)
{
	int local_value = get_value(k, row, col);
	int res = 0;
	for(int i = row - 1; i <= row + 1; ++i)
		for(int j = col - 1; j <= col + 1; ++j)
		{
			if(i < 0 || i >= height || j < 0 || j >= width) continue;
			int value = get_value(k, i, j);
			res = max(res, abs(value - local_value));
		}
	return res;
}

int main()
{
	while(cin >> width && width)
	{
		v_in.clear();
		v_edge.clear();
		int value, length, index = 0;
		while(cin >> value >> length && value + length)
		{
			rle item;
			item.value = value;
			item.length = length;
			item.index = index;
			v_in.push_back(item);
			index += length;
		}
		n = v_in[v_in.size() - 1].index + v_in[v_in.size() - 1].length;
		height = n/width;
		for(int k = 0; k < v_in.size(); ++k)
		{
			int row = v_in[k].index/width;
			int col = v_in[k].index%width;
			for(int i = row - 1; i <= row + 1; ++i)
				for(int j = col - 1; j <= col + 1; ++j)
				{
					if(i < 0 || i >= height || j < 0 || j >= width) continue;
					int res = get_edge(k, i, j);
					int index = i*width + j;
					edge item;
					item.value = res;
					item.pos = index;
					v_edge.push_back(item);
				}
		}

		int row = height - 1;
		int col = 0;
		int k = v_in.size() - 1;
		for(int i = row - 1; i <= row + 1; ++i)
			for(int j = col - 1; j <= col + 1; ++j)
			{
				if(i < 0 || i >= height || j < 0 || j >= width) continue;
				int res = get_edge(k, i, j);
				int index = i*width + j;
				edge item;
				item.value = res;
				item.pos = index;
				v_edge.push_back(item);
			}

		sort(v_edge.begin(), v_edge.end());
		cout << width << endl;

		edge temp = v_edge[0];
		for(int i = 1; i < v_edge.size(); ++i)
		{
			if(v_edge[i].value == temp.value) continue;
			cout << temp.value << " " << v_edge[i].pos - temp.pos << endl;
			temp = v_edge[i];
		}
		cout << temp.value << " " << n - temp.pos << endl;
		cout << "0 0 " << endl;
	}
	cout << "0" << endl;
	return 0;
}