Clang Tidy Fixes

Change-Id: I65558225cc537e86428caa5081bde165968bfab3

internal/ceres/block_sparse_matrix.cc

diff --git a/internal/ceres/block_sparse_matrix.cc b/internal/ceres/block_sparse_matrix.cc
index 0e05693..053b3c0 100644
--- a/internal/ceres/block_sparse_matrix.cc
+++ b/internal/ceres/block_sparse_matrix.cc
@@ -48,7 +48,7 @@
 
 namespace {
 void ComputeCumulativeNumberOfNonZeros(std::vector<CompressedList>& rows) {
-  if (!rows.size()) {
+  if (rows.empty()) {
     return;
   }
   rows[0].cumulative_nnz = rows[0].nnz;

internal/ceres/block_sparse_matrix_test.cc

diff --git a/internal/ceres/block_sparse_matrix_test.cc b/internal/ceres/block_sparse_matrix_test.cc
index 62bb0f4..cfed041 100644
--- a/internal/ceres/block_sparse_matrix_test.cc
+++ b/internal/ceres/block_sparse_matrix_test.cc
@@ -30,8 +30,11 @@
 
 #include "ceres/block_sparse_matrix.h"
 
+#include <algorithm>
 #include <memory>
+#include <random>
 #include <string>
+#include <vector>
 
 #include "ceres/casts.h"
 #include "ceres/crs_matrix.h"

internal/ceres/evaluation_benchmark.cc

diff --git a/internal/ceres/evaluation_benchmark.cc b/internal/ceres/evaluation_benchmark.cc
index 1fdc8d2..b18f563 100644
--- a/internal/ceres/evaluation_benchmark.cc
+++ b/internal/ceres/evaluation_benchmark.cc
@@ -29,6 +29,7 @@
 // Authors: dmitriy.korchemkin@gmail.com (Dmitriy Korchemkin)
 
 #include <memory>
+#include <random>
 #include <string>
 #include <vector>