题目链接:传送门
题意:
n个学生站一行,老师给每个学生发至少一个糖
相邻学生,a[i] > a[i-1] 的话,那么右边学生的糖一定要发得比左边学生的糖多
问你满足条件这个老师总共最少的发多少糖
题解:
向左向右连续递增的话发的糖数量就递增,否则就是1个
取一个max即可
#include<bits/stdc++.h> using namespace std; #pragma comment(linker, "/STACK:102400000,102400000") #define ls i<<1 #define rs ls | 1 #define mid ((ll+rr)>>1) #define pii pair<int,int> #define MP make_pair typedef long long LL; const long long INF = 1e18+1LL; const double Pi = acos(-1.0); const int N = 5e5+10, M = 1e2+20,inf = 2e9,mod = 1e9+7; int a[N],n,dp1[N],dp2[N]; int main() { scanf("%d",&n); for(int i = 1; i <= n; ++i) scanf("%d",&a[i]); for(int i = 1; i <= n; ++i) { dp1[i] = 1; dp2[i] = 1; } for(int i = 2; i <= n; ++i) { if(a[i] > a[i-1]) dp1[i] = dp1[i-1] + 1; } for(int i = n-1; i >= 1; --i) { if(a[i+1] < a[i]) dp2[i] = dp2[i+1] + 1; } LL ans = 0; for(int i = 1; i <= n; ++i) ans += max(dp1[i],dp2[i]); cout<<ans<<endl; return 0; }