64 lines
1.2 KiB
C++
64 lines
1.2 KiB
C++
|
// Source : https://oj.leetcode.com/problems/jump-game-ii/
|
||
|
|
// Author : Hao Chen
|
||
|
|
// Date : 2014-07-18
|
||
|
|
|
||
|
|
#include <iostream>
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
int jump(int A[], int n) {
|
||
|
|
if (n<=1) return 0;
|
||
|
|
|
||
|
|
int steps = 0;
|
||
|
|
int coverPos = 0;
|
||
|
|
for (int i=0; i<=coverPos&& i<n; ){
|
||
|
|
if (A[i]==0) return -1;
|
||
|
|
if(coverPos < A[i]+i){
|
||
|
|
coverPos = A[i]+i;
|
||
|
|
steps++;
|
||
|
|
}
|
||
|
|
if (coverPos >= n-1){
|
||
|
|
return steps;
|
||
|
|
}
|
||
|
|
int nextPos=0;
|
||
|
|
int maxDistance=0;
|
||
|
|
for(int j=i+1; j<=A[i]+i; j++){
|
||
|
|
if ( A[j]+j > maxDistance ) {
|
||
|
|
maxDistance = A[j]+j;
|
||
|
|
nextPos = j;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
i = nextPos;
|
||
|
|
}
|
||
|
|
return steps;
|
||
|
|
}
|
||
|
|
|
||
|
|
void printArray(int a[], int n){
|
||
|
|
cout << "{ ";
|
||
|
|
for(int i=0; i<n; i++){
|
||
|
|
if(i) cout << ", ";
|
||
|
|
cout << a[i];
|
||
|
|
}
|
||
|
|
cout << " } ";
|
||
|
|
}
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
#define TEST(a) printArray(a, sizeof(a)/sizeof(int)); cout<<jump(a, sizeof(a)/sizeof(int))<<endl;
|
||
|
|
|
||
|
|
int a1[]={0};
|
||
|
|
TEST(a1);
|
||
|
|
|
||
|
|
int a2[]={1};
|
||
|
|
TEST(a2);
|
||
|
|
|
||
|
|
int a3[]={3,2,1,0,4};
|
||
|
|
TEST(a3);
|
||
|
|
|
||
|
|
int a4[]={2,3,1,1,4};
|
||
|
|
TEST(a4);
|
||
|
|
|
||
|
|
int a5[]={1,2,3};
|
||
|
|
TEST(a5);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|