modified mapper_count
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
Merge branch 'master' of https://github.com/wangweinan/HW3_CS294
modified _2