[UVa 11093] 环形跑道（Just Finish it up）

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;

struct SNode {
int iIndex;
int iAdd, iNeed;
SNode * pNext;
};

SNode g_arrNode[100011];
int g_iNodeTot;

bool g_arrVisited[100011];

bool Solve(int iStart, int & iStop)
{
SNode * pNode = &g_arrNode[iStart];
int iRest = 0;
bool b = false;
while (true)
{
g_arrVisited[pNode->iIndex] = true;
iRest += pNode->iAdd - pNode->iNeed;

iStop = pNode->iIndex;

if (pNode->iIndex == iStart && b)
return true;
if (iRest < 0)
return false;

pNode = pNode->pNext;
b = true;
}
}

int main()
{
int iDataTot; cin >> iDataTot;
for (int iData = 1; iData <= iDataTot; iData++)
{
memset(g_arrNode, 0, sizeof(g_arrNode));
memset(g_arrVisited, 0, sizeof(g_arrVisited));

cin >> g_iNodeTot;

for (int i = 1; i <= g_iNodeTot; i++)
{
g_arrNode[i].iIndex = i;
cin >> g_arrNode[i].iAdd;
if (i != g_iNodeTot)
g_arrNode[i].pNext = &g_arrNode[i + 1];
else
g_arrNode[i].pNext = &g_arrNode[1];
}

for (int i = 1; i <= g_iNodeTot; i++)
cin >> g_arrNode[i].iNeed;

int iStart = 1, bResult = false;
while (true)
{
if (bResult = Solve(iStart, iStart))
break;

iStart++;
if (g_arrVisited[iStart] || iStart > g_iNodeTot)
break;
}

if (bResult)
printf("Case %d: Possible from station %d\n", iData, iStart);
else
printf("Case %d: Not possible\n", iData);
}

return 0;
}