【动态规划】[luoguP1508]Likecloud-吃、吃、吃

题目

刚学动态规划的时候都做过入门题 — 数字金字塔

倒着推

代码如下

#include<iostream>#include<cstdio>#include<cctype>    using namespace std;    #define in = read();    typedef long long ll;    typedef unsigned int ui;    const ll size = 200 + 10;        int m , n;        int map[size][size];        int ans;        int f[size][size];inline ll read(){        ll num = 0 , f = 1;    char ch = getchar();        while(!isdigit(ch)){                if(ch == '-')   f = -1;                ch = getchar();        }        while(isdigit(ch)){                num = num*10 + ch - '0';                ch = getchar();        }        return num*f;}int main(){        n in;    m in;        for(register int i=1;i<=n;i++)                for(register int j=1;j<=m;j++)                        map[i][j] in;        for(register int i=1;i<=m;i++)                f[1][i] = map[1][i];        for(register int i=2;i<=n;i++)                for(register int j=1;j<=m;j++)                        f[i][j] = max(f[i - 1][j - 1] , max(f[i - 1][j] , f[i - 1][j + 1])) + map[i][j];        ans = max(f[n][m>>1] , max(f[n][(m>>1) + 1] , f[n][(m>>1) + 2]));        printf("%d" , ans);}//COYG