Submission #35555875

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Source Code Expand

#include <bits/stdc++.h>
#define rep(i,a,n) for (int i=a;i<(int)n;i++)
int read(){int r;scanf("%d",&r);return r;}

const int N=50;
int a[N+10]; // 1-index
int dp[N+10][N+10][N+10][N+10];
void setMax(int&a,int b){a=std::max(a,b);}
int main() {
  int n=read();
  rep(i,1,n+1)a[i]=read();
  rep(i,1,n+1)rep(l,1,a[i]+1)rep(r,a[i],N+1)dp[i][i][l][r]=1;
  rep(len,2,n+1)rep(i,1,n-(len-1)+1)rep(l,1,N+1)rep(r,l,N+1){
    int j=i+(len-1);
    int &o=dp[i][j][l][r];
    if(l!=r)setMax(o,dp[i][j][l][r-1]); // r不出现在X中
    rep(k,i,j+1)if(a[k]==r)rep(v,l,r+1)setMax(o,1+dp[i][k-1][l][v]+dp[k+1][j][v][r]); // 无效的范围贡献刚好是0
  }
  printf("%d\n",dp[1][n][1][N]);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int read()’:
./Main.cpp:3:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
    3 | int read(){int r;scanf("%d",&r);return r;}
      |                  ~~~~~^~~~~~~~~

Judge Result