Revise the algorithm given for finding the maximum subsequence sum so that it finds the indices (i,j) of the subsequence as well.

/** * Recursive maximum contiguous subsequence sum algorithm. * Finds maximum sum in subarray spanning a[left..right]. 3 * Does not attempt to maintain actual best sequence. */ int maxSumRec( const vector & a, int left, int right ) { if( left == right ) // Base case 4 if( a[ left ] > 0 ) return a[ left ]; 9. 10 else 11 12 return 0; 13 int center = ( left + right ) / 2; 14 = maxSumRec ( a, left, center ); int maxRightSum = maxSumRec( a, center + 1, right ); 15 int maxLeftSum 16 17 int maxLeftBorderSum = 0, leftBorderSum = 0; 18 for( int i = center; i >= left; --i ) { leftBorderSum += a[ i ]; 19 20 21 if( leftBorderSum > maxLeftBorderSum ) 22 maxLeftBorderSum = leftBorderSum; 23 } 24 25 26 int maxRightBorderSum = 0, rightBorderSum = 0; for( int j = center + 1; j maxRightBorderSum ) 27 28 29 30 31 maxRightBorderSum = rightBorderSum; } 32 33 return max3( maxLeftSum, maxRightSum, 34 maxLeftBorderSum + maxRightBorderSum ); 35 } 36 37 /** 38 * Driver for divide-and-conquer maximum contiguous 39 40 subsequence sum algorithm. */ int maxSubSum3( const vector & a ) 41 42 { 43 return maxSumRec( a, 0, a.size( ) - 1 ); 44 } 45