【杭电】[4004]The Frog's Games

#include<stdio.h>
#include<algorithm>
using namespace std;
int a[500200];
int L,n,m;
bool judge(int x) {
int cnt=0,t=0;
for(int i=1; i<=n; i++) {
if(a[i]-a[i-1]>x)
return false;
if(a[i]-t>x) {
cnt++;
t=a[--i];
}
}
if(cnt+1<=m)
return true;
else
return false;
}
int main() {
while(scanf("%d %d %d",&L,&n,&m)!=EOF) {
for(int i=1; i<=n; i++)
scanf("%d",&a[i]);
a[0]=0,a[++n]=L;
sort(a,a+n+1);
int l=0,r=L,res;
while(l<=r) {
int mid=(l+r)/2;
if(judge(mid)) {
res=mid;
r=mid-1;
} else
l=mid+1;
}
printf("%d\n",res);
}
return 0;
}