Recursive, dynamic programming, finding the shortest path, help Jimmy

Title Link: http://poj.org/problem?id=1661

Problem Solving Report:

1. Every time a mouse comes to a plank, there are only two ways to go, and you can use recursion

#include <stdio.h>#include<string.h>#include<stdlib.h>#include<memory.h>#define_max 1010#defineINF 0x3f3f3f3fstructplatform{intlx//the coordinates of the left side of the plank    intRx//the coordinates of the right end of the plank    intH//the height of the plank from the ground} P[_max];intMax,n;intLeftmin[_max];//The shortest time from the left end of each plank to the groundintRightmin[_max];intMy_compare (Const void*e1,Const void*E2)//used in fast sorting, higher planks are placed in front{    structPlatform *p1,*P2; P1=(structplatform*) E1; P2=(structplatform*) E2; returnP2->h-p1->h;}intMintime (intLintFlag//jumping from a wooden board numbered L, flag indicates the direction to jump from the plank, flag=1 to the left{    inty=p[l].h; intI,x,ltime,rtime; if(flag) x=P[L].LX;//X is Jimmy's coordinates, which means the left end of the plank .    Elsex=P[l].rx;  for(i=l+1; i<=n; i++)//start looking for planks .    {        if(p[i].lx<=x&&p[i].rx>=x) Break; }    if(i<=n)//find the plank, but it will fall .    {        if(y-p[i].h>MAX)returnINF; }    Else//There's no wood underneath.    {        if(y>MAX)returnINF; Else returnY//no plank jumps straight down} ltime=y-p[i].h+x-P[I].LX; Rtime=y-p[i].h+p[i].rx-x; if(leftmin[i]==-1) Leftmin[i]=mintime (I,1); if(rightmin[i]==-1) Rightmin[i]=mintime (I,0); Ltime+=Leftmin[i]; Rtime+=Rightmin[i]; if(ltime<rtime)returnLtime; Else returnRtime;}intMain () {intI,cases,x,y; scanf ("%d",&cases);  while(cases--) {scanf ("%d%d%d%d",&n,&x,&y,&MAX); memset (Leftmin,-1,sizeof(leftmin)); memset (Rightmin,-1,sizeof(rightmin)); p[0].lx=x; p[0].rx=x; p[0].h=y;  for(i=1; i<=n; i++) {scanf ("%d%d%d",&p[i].lx,&p[i].rx,&p[i].h); } qsort (P,n+1,sizeof(structPlatform), my_compare); printf ("%d\n", Mintime (0,1)); }    return 0;}

Recursive, dynamic programming, finding the shortest path, help Jimmy