HDU 4004 The Frog's Games [二分]

二分法找答案

#include <cstdio>#include <iostream>#include <algorithm>using namespace std;const int MAXN = 500000 + 9;int l, n, m;int a[MAXN];bool ok(int x){  //cout << x << endl;  int s = 0; //开始跳的点  int i = 1; //要跳到的点  int total = 0;  while (i <= n + 1)  {    if (a[i] - a[s] > x) return false;    while (i <= n + 1 && a[i] - a[s] <= x) {      i++;    }    total++;    s = i - 1;  }  if (total <= m) return true;  return false;}void solve(){  a[0] = 0;  for (int i = 1; i <= n; i++) {    scanf("%d", &a[i]);  }  a[n + 1] = l;  sort(a, a + n + 2);  int p = 0, q = l;  while(p < q) {    int mid = (p + q) / 2;    if(ok(mid)) q = mid;    else p = mid + 1;  }  printf("%d\n", q);}int main(){  //freopen("in.txt", "r", stdin);  while (scanf("%d%d%d", &l, &n, &m) != EOF) {    solve();  }}