蒟蒻刷DP题80分求助

#include <iostream>
#include <cstdio>
#include <algorithm>
using std::sort;

struct Node
{
	int x, y, h;
}s[10900];

struct OriginalGraph
{
	int h, w;
}g[109][109];

int r, c, ans;

int v(int pos1, int pos2)
{
	return ((pos1-1)*r+pos2);
}

int comp(const Node s1, const Node s2)
{
	return s1.h>s2.h;
}

int main()
{
	scanf("%d%d", &r, &c);
	for(register int i=1; i<=r; ++i)
	{
		for(register int j=1; j<=c; ++j)
		{
			scanf("%d",&g[i][j].h);
			s[v(i,j)].h=g[i][j].h;
			s[v(i,j)].x=i;
			s[v(i,j)].y=j;
			g[i][j].w=1;
		}
	}
	sort(s+1, s+r*c+1, comp);
	for(register int i=1; i<=r*c; ++i)
	{
		if(g[s[i].x-1][s[i].y].h>g[s[i].x][s[i].y].h&&g[s[i].x-1][s[i].y].w+1>g[s[i].x][s[i].y].w&&s[i].x-1>0)
		{
			g[s[i].x][s[i].y].w=g[s[i].x-1][s[i].y].w+1;
		}
		if(g[s[i].x][s[i].y-1].h>g[s[i].x][s[i].y].h&&g[s[i].x][s[i].y-1].w+1>g[s[i].x][s[i].y].w&&s[i].y-1>0)
		{
			g[s[i].x][s[i].y].w=g[s[i].x][s[i].y-1].w+1;
		}
		if(g[s[i].x+1][s[i].y].h>g[s[i].x][s[i].y].h&&g[s[i].x+1][s[i].y].w+1>g[s[i].x][s[i].y].w&&s[i].x+1<=r)
		{
			g[s[i].x][s[i].y].w=g[s[i].x+1][s[i].y].w+1;
		}
		if(g[s[i].x][s[i].y+1].h>g[s[i].x][s[i].y].h&&g[s[i].x][s[i].y+1].w+1>g[s[i].x][s[i].y].w&&s[i].y+1<=c)
		{
			g[s[i].x][s[i].y].w=g[s[i].x][s[i].y+1].w+1;
		}
		if(g[s[i].x][s[i].y].w>ans)
		{
			ans=g[s[i].x][s[i].y].w;
		}
	}
	printf("%d",ans);
	return 0;
}