foo.cc: In function 'int main()':
foo.cc:12:13: warning: variable 'tem' set but not used [-Wunused-but-set-variable]
   12 |         int tem = 0;
      |             ^~~
foo.cc:34:47: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
   34 |                         arr[i][j] = arr[i+1][j] + arr[i+1][j+1];
      |                                     ~~~~~~~~~~^
foo.cc:32:34: note: within this loop
   32 |                 for (int j = 1;j <= 4;j++)
      |                                ~~^~~~
foo.cc:17:47: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
   17 |                         arr[i][j] = arr[i+1][j] + arr[i+1][j+1];
      |                                     ~~~~~~~~~~^
foo.cc:15:34: note: within this loop
   15 |                 for (int j = 1;j <= 4;j++)
      |                                ~~^~~~
foo.cc:8:14: warning: array subscript 4 is above array bounds of 'int [4][4]' [-Warray-bounds]
    8 |         arr[4][1] = a;
      |         ~~~~~^
foo.cc:3:5: note: while referencing 'arr'
    3 | int arr[4][4];
      |     ^~~
foo.cc:9:14: warning: array subscript 4 is above array bounds of 'int [4][4]' [-Warray-bounds]
    9 |         arr[4][2] = 1;
      |         ~~~~~^
foo.cc:3:5: note: while referencing 'arr'
    3 | int arr[4][4];
      |     ^~~
foo.cc:10:14: warning: array subscript 4 is above array bounds of 'int [4][4]' [-Warray-bounds]
   10 |         arr[4][3] = 1;
      |         ~~~~~^
foo.cc:3:5: note: while referencing 'arr'
    3 | int arr[4][4];
      |     ^~~
foo.cc:11:17: warning: array subscript 4 is above array bounds of 'int [4]' [-Warray-bounds]
   11 |         arr[4][4] = b;
      |         ~~~~~~~~^
foo.cc:3:5: note: while referencing 'arr'
    3 | int arr[4][4];
      |     ^~~
foo.cc:26:14: warning: array subscript 4 is above array bounds of 'int [4][4]' [-Warray-bounds]
   26 |         arr[4][2] = 2;
      |         ~~~~~^
foo.cc:3:5: note: while referencing 'arr'
    3 | int arr[4][4];
      |     ^~~
foo.cc:27:14: warning: array subscript 4 is above array bounds of 'int [4][4]' [-Warray-bounds]
   27 |         arr[4][3] = 2;
      |         ~~~~~^
foo.cc:3:5: note: while referencing 'arr'
    3 | int arr[4][4];
      |     ^~~

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