usaco 1.5.1

下决心要要坚持的，可是没有动力真的很难啊，虽然这个题是绝对的水题，但为了保持连续性，还是要贴出来，以兹鼓励。

/*ID: xincaor1LANG: C++TASK: numtri*/ #include <algorithm>#include <climits>#include <cstdio>#include <iostream>#include <cstring>using namespace std; int main(){int sum[2][1005],readin[1005],flag=0;int r,i,j;freopen("numtri.in","r",stdin);freopen("numtri.out","w",stdout);cin>>r;memset(sum,0,sizeof(sum));for(i=1;i<=r;i++){for(j=1;j<=i;j++)cin>>readin[j];for(j=1;j<=i;j++)sum[!flag][j]=max(sum[flag][j],sum[flag][j-1])+readin[j];flag=!flag;}int maxsum=0;for(i=1;i<=r;i++)if(sum[flag][i]>maxsum)maxsum=sum[flag][i];cout<<maxsum<<endl;return 0;}