/in/foo.cc: In function 'int main()':
/in/foo.cc:30:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
         for(int l=2;l<=i;l++)//从左往右推 从左往右走的情况更新
         ^~~
/in/foo.cc:32:13: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for'
             f[i][1]=min(f[i][1],f[i][i]+a[i][1]);
             ^